Sabatier principle of metal-support interaction for design of ultrastable metal nanocatalysts

Interface control in TiO2/BaTiO3 ferroelectric heterostructures: A bidirectional catalytic pathway toward high-performance Li-S batteries

Li-S batteries (LSBs), noted for their high energy density and low cost, face challenges due to sluggish lithium polysulfide (LiPS) redox kinetics and complex phase transformations during charge/discharge cycles. Herein, we introduce a novel hollow nanocomposite, a titanium oxide/barium titanate (TiO2/BaTiO3) heterostructure with an ultrathin carbon coating, designed to act as a bidirectional electrocatalyst, enhancing the sequential conversion of sulfur (S8) to Li2S4 and then to lithium sulfide (Li2S). The ferroelectric nature of BaTiO3 enhances LiPS adsorption, reducing the shuttling effect and improving battery performance. The interface-induced electric field directs LiPS migration to TiO2, facilitating the redox process. An applied electric field polarizes the heterostructure, optimizing the dipole moment of BaTiO3 and further enhancing performance. Electrochemical measurements and theoretical calculations confirm the superior electrocatalytic activity of TiO2/BaTiO3@C for LiPS redox kinetics. The composite electrode achieves a high initial capacity of 836 mAh g-1 at 1C, retaining 64 % of its capacity after 400 cycles with a low fading rate of 0.075 % per cycle. Under practical operation conditions (sulfur areal loading: 6.02 mg cm-2; electrolyte/sulfur (E/S) ratio: 6.5 μL mg-1), the as-fabricated LSBs still demonstrate good areal capacities of 5.18, 4.09, 3.84, 3.64, and 3.15 mAh cm-2, respectively, at current densities from 0.05 to 0.5C. This study elucidates the critical synergy between self-induced electric fields and heterostructure engineering in polysulfide conversion, providing fundamental guidance for designing advanced catalysts in high-energy LSBs and related electrochemical energy systems.

Design of Ni-FAU Zeolite Bifunctional Materials for Integrated Carbon Dioxide Capture and Methanation: Construction of ultrafine NiO nanoparticles

The Integrated Carbon Dioxide (CO2) Capture and Methanation (ICCU-Met) technology has emerged as a promising strategy for reducing CO2 emissions while producing methane (CH4) fuel. However, a significant challenge in this process is the absence of bifunctional materials (DFMs) that simultaneously possess highly dispersed metal sites and stable adsorbent structures under variable temperature conditions. This is particularly problematic because existing nickel-based (Ni) bifunctional materials are prone to metal sintering and structural degradation at high temperatures. In this study, highly dispersed ultrafine Ni metal confined in Faujasite (FAU) zeolite support bifunctional materials were synthesized with remarkable CO2 capture capacity of 2.77 mmol CO2/g and CH4 yield of 654.4 μmol CH4/g in the ICCU-Met reaction. Notably, the 8Ni-FAU DFMs maintained their initial activity after 10 drastic heating-cooling cycles between 70 °C and 300 °C. Moreover, the CO2 adsorption, CH4 yield, and CH4 selectivity of 8Ni-FAU DFMs under simulated real flue gas atmosphere were 0.43 mmol/g, 264.3 μmol/g, and 99.5 %, respectively. This stability is attributed to the successful immobilization of ultrafine NiO nanoparticles within the FAU zeolite pores, which enhanced the metal-support interactions and promoted the formation of oxygen vacancies. These features facilitated the efficient adsorption and decomposition of CO2, as well as the activation and dissociation of H2. Both in situ DRIFTs experiments and density functional theory (DFT) calculations confirmed that the 8Ni-FAU DFMs proceed via the formate pathway. Additionally, it was found that the strong interaction between the active Ni metal and the FAU support reduces the CO2 adsorption energy and lowers the energy barrier for the generation of formate (HCOO*) active intermediates, thus guiding the ICCU-Met reaction.

Tailored electronic interaction between metal-support trigger reverse hydrogen spillover for efficient hydrogen evolution

The triggering of fast hydrogen spillover through regulating the charge rearrangement of the metal-support serves as a crucial mechanism for decoupling the activity of HER catalysts from the adsorption properties, which not only contributes to enhancing the performance of the catalysts but also facilitates the production of green hydrogen. Herein, we tailor the electronic interaction between two-dimensional (2D) nitrogen-doped MoC (N-MoC) nanosheets and anultra-low content of Pt nanoclusters (1 wt%) to trigger reverse hydrogen spillover and modulate the electronic structure of Pt, thus achieving efficient and stable HER. Compared to Pt/C (0.229 A mgPt-1), Pt/N-MoC demonstrates a mass activity of 12.945 A mgPt-1, representing an enhancement of nearly 57.5 times. Notably, the excellent electrocatalytic performance was verified in the proton exchange membrane water electrolyzer configuration. Combining experimental and theoretical analysis, anultra-low load of Pt nanocluster (1 wt%) integrated with N-MoC nanosheets can induce a charge transfer from N-MoC to Pt, thus modulating the d-band center of Pt to improve the hydrogen adsorption properties and achieving fast hydrogen desorption (ΔG = 0.019 eV); furthermore, a small difference in work function between Pt nanoclusters and the N-MoC were achieved to dilute charge accumulation between the metal-support interface, thus reducing the energy barrier of hydrogen spillover.

Prediction of C2N-Supported Double-Atom Catalysts with Individual/Integrated Descriptors for Electrochemical and Thermochemical CO2 Reduction

Electrochemical/thermochemical CO2 reduction reactions (CO2RR) on double-atom catalysts (DACs) have emerged as a novel frontier in energy and environmental catalysis. However, the lack of investigation of the underlying structure-property relationship greatly limits the rational design and practical application of related catalysts. Herein, we carried out a comprehensive theoretical study on CO2RR catalyzed by a series of C2N-supported transition metals to shed light on this issue. We demonstrate that the activity of DAC can be obviously improved by judicious manipulation of metal type, and CoNi with the highest reactivity and excellent selectivity is identified as the most promising candidate for both electroreduction and thermoreduction processes. Then, based on systemically electronic and structural analysis, various quantitative structure-property relationships are established. The results reveal that key interaction and reaction properties of elementary steps can be quantitatively determined directly from individual descriptors, including key species, charge transfer, d-orbital center, bond length, spectroscopic signals, etc, while for total reaction, the integrated descriptors designed by a novel and effective three-step strategy have much better performance. The proposed ability of quantitative prediction of the catalytic property utilizing physically interpretable parameters can significantly broaden the applicability of catalytic descriptors for materials design, thus leading to indispensable guidelines for related DACs.

Enhanced photocatalytic H2O2 production via a facile atomic diffusion strategy near tammann temperature for single atom photocatalysts

Current methods for preparing single atom catalysts (SACs) often suffer from challenges such as high synthesis temperatures, complicated procedures, and expensive equipment. In this study, a facile and universal atomic diffusion strategy near Tamman temperature (AD-TTam) was proposed for the synthesis of semiconductor supported non-noble metal SACs, denoted as M/S, where M = Fe, Ni, Cu, Al and S = ZnO, C3N4, TiO2(A), In2O3. Based on the empirical TTam (c.a. 1/2 of the melting point) phenomenon, this strategy utilized the higher atomic mobility in bulk metals near TTam to facilitate the migration of metal atoms to the support surface, thereby forming SACs at a relatively low temperature. A series of M/S SACs prepared using the AD-TTam strategy all exhibited enhanced photocatalytic H2O2 production activity. Notably, Cu/ZnO achieved an H2O2 production rate of 986.7 μmol g-1h-1 through the synergistic dual pathways of the water oxidation reaction and the oxygen reduction reaction, marking a 5.4-fold increase compared to pure ZnO. The introduction of Cu single atoms significantly improved the separation and migration of charge carriers in Cu/ZnO, thereby promoting the catalytic conversion of H2O and O2. Overall, this strategy is easily extensible at relatively low calcination temperatures and presents great potential for industrial applications.

Emerging Trends in Two-Dimensional Nanomaterials for Electrocatalytic Nitrate-to-Ammonia Conversion

Electrocatalytic nitrate reduction to ammonia (ENRA) has emerged as a promising strategy due to its dual functionality in wastewater treatment and sustainable ammonia synthesis. Two-dimensional (2D) nanomaterials offer the exposure of highly active sites, tunability of the electronic structure, and enhanced mass transfer capabilities, thereby optimizing the atomic-scale kinetics of the nitrate reduction reaction and improving the ammonia synthesis efficiency. This review provides a comprehensive overview of recent advances in the field of 2D nanomaterials. Initially, fundamental mechanisms are examined. Subsequently, the paper explores the advantages of 2D materials, including metallic variants (e.g., metals, metal oxides, metal hydroxides, metal carbides, metal nitrides, metal borides, and 2D-confined single-atom catalysts) as well as 2D nonmetallic materials, focusing on their roles in nitrate activation and proton-coupled electron transfer processes. Finally, this review provides a prospective development of 2D catalysts, addressing the challenges related to long-term stability under industrial-grade current densities and outlining potential avenues for future research in this area.

Sustainable and cost-efficient hydrogen production using platinum clusters at minimal loading

Proton exchange membrane water electrolysis stands as a promising technology for sustainable hydrogen production, although its viability hinges on minimizing platinum (Pt) usage without sacrificing catalytic efficiency. Central to this challenge is enhancing the intrinsic activity of Pt while ensuring the stability of the catalyst. We herein present a Mo2TiC2 MXene-supported Pt nanocluster catalyst (Mo2TiC2-PtNC) that requires a minimal Pt content (36 μg cm-2) to function, yet remains highly active and stable. Operando spectroscopy and theoretical simulation provide evidence for anomalous charge transfer from the MXene substrate to PtNC, thus generating highly efficient electron-rich Pt sites for robust hydrogen evolution. When incorporated into a proton exchange membrane electrolyzer, the catalyst affords more than 8700 h at 200 mA cm-2 under ambient temperature with a decay rate of just 2.2 μV h-1. All the performance metrics of the present Mo2TiC2-PtNC catalysts are on par with or even surpass those of current hydrogen evolution electrocatalysts under identical operation conditions, thereby challenging the monopoly of high-loading Pt/C-20% in the current electrolyzer design.

Transition metal-doped cobalt phosphide for efficient hydrazine oxidation: a density functional theory study

Hydrazine oxidation reaction (HzOR) provides a sustainable alternative to the sluggish oxygen evolution reaction (OER), with a low theoretical thermodynamic potential (-0.33 V vs. RHE). However, developing efficient non-precious-metal catalysts for HzOR remains challenging. Here, we employed density functional theory (DFT) simulations to systematically investigate the mechanism of transition metal atoms doping (Au, Cr, Fe, Mn, Mo, Ni, Pd, Pt) to boost the N-H bond cleavage in HzOR. Among the studied dopants, Cr and Mn exhibit exceptional catalytic activity, achieving ultralow ΔG for RDS of -0.02 eV (CoP-Cr) and 0.02 eV (CoP-Mn), significantly lower than the high-coordination cobalt sites on undoped CoP (0.11 eV). CoP-Cr aligns with descriptor-driven optimization, while CoP-Mn operates via dopant-induced charge redistribution. Furthermore, we identified the adsorption free energy of N-NH2 (ΔGad-N2H2-1) as a robust descriptor for catalytic activity in the reaction pathway involving distal configuration, showing strong correlations with ΔG of RDS. This work proposed a dual design strategy-descriptor-driven optimization (CoP-Cr) and charge-redistribution enhancement (CoP-Mn)-as a roadmap for developing earth-abundant, high-performance catalysts. These insights pave the way for advancing sustainable hydrogen production and environmental remediation technologies.

Particle Hopping and Coalescence of Supported Au Nanoparticles in Harsh Reactive Environments

Sintering of supported metal nanoparticles (NPs) is a general and important phenomenon in materials and catalysis science. A consensus view is that it takes place either via the Ostwald ripening (OR) or particle migration and coalescence (PMC) mechanism through the substrate, but how sintering occurs under high gas pressure and high temperature has not been addressed. Here, we perform millisecond-scale environmental kinetic Monte Carlo (EKMC) simulations combined with density functional theory (DFT) calculations to reveal a unique through-space sintering mechanism, particle hopping and coalescence (PHC). Under high CO pressure and high temperature, the coalescence of Au NPs takes place through NP hopping up from the anatase TiO2(101) substrate and mass transfer via the gas phase. When the sintered floating NP reaches a critical size, it spontaneously redeposits onto the substrate. This process is driven by the preference of interfacial Au atoms of small NPs to interact with CO rather than the substrate at a high CO chemical potential. The PHC mechanism implies that NP sintering and intersubstrate catalyst transfer may occur easier than expected during reactions and provides a distinct perspective to understand catalyst thermal deactivation under harsh operando conditions.

Supra-Strong Metal-Support Interaction in Oxide-Solid-Solution-Derived Transition Metal Catalysts

Transition metal catalysts with electron-deficient active sites (Mδ+) can exhibit unique activity and selectivity in hydrogenation reactions but are prone to deactivation under high-temperature reaction conditions due to the reduction of Mδ+. Here the existence of a supra-strong metal-support-interaction in oxide-solid-solution-derived nickel catalysts are reported, which greatly enhances the stability of Niδ+ against reduction. It is found that the reduction of Ni species from solid solutions of NiO and magnesium aluminum spinel occurs at higher temperatures compare to pristine NiO, which is attributed to the strengthened binding of Ni atoms to ligand oxygen atoms for the former. The strength of the metal-support interaction in the final catalysts can be tuned by controlling the calcination temperature of the impregnation process and thus the degree of solid solution formation from separated oxide precursors. Notably, the optimized Ni catalyst with durable electron-deficient sites exhibits a sustained CO output with a 100% selectivity and ≈30% CO2 conversion at 600 °C in catalyzing the reverse water-gas shift reaction.

A self-regenerating Pt/Ge-MFI zeolite for propane dehydrogenation with high endurance

Supported noble metal cluster catalysts are typically operated under severe conditions involving switching between reducing and oxidizing atmospheres, causing irreversible transformation of the catalyst structure and thereby leading to permanent deactivation. We discovered that various platinum (Pt) precursors spontaneously disperse in a germanium-MFI (Ge-MFI) zeolite, which opposes the Ostwald ripening phenomenon, producing self-regenerating Pt/Ge-MFI catalysts for propane dehydrogenation. These catalysts reversibly switch between Pt clusters and Pt single atoms in response to reducing reaction and oxidizing regeneration conditions. This environmental adaptability allows them to completely self-regenerate over 110 reaction and regeneration cycles in propane dehydrogenation, and they exhibited unprecedented sintering resistance when exposed to air at 800°C for 10 days. Such spontaneous metal dispersion in a Ge-MFI zeolite is a robust and versatile methodology for fabricating various rhodium, ruthenium, iridium, and palladium cluster catalysts.

In Situ Time-Resolved X-ray Absorption Spectroscopy Unveils Partial Re-Oxidation of Tellurium Cluster for Prolonged Lifespan in Hydrogen Evolution

Efficient and long-lasting electrocatalysts are one of the key factors in determining their large-scale commercial viability. Although the fundamentals of deactivation and regeneration of electrocatalysts are crucial for understanding and sustaining durable activity, little has been conducted on metalloids compared to metal-derived ones. Herein, by virtue of in situ seconds-resolved X-ray absorption spectroscopy, we discovered the chemical evolution during the deactivation-regeneration cycles of tellurium clusters supported by nitrogen-doped carbon (termed Te-ACs@NC) as a high-performance electrocatalyst in the hydrogen evolution reaction (HER). Through in situ electrochemical reduction, Te-ACs@NC, which had been deactivated due to surface phase transitions in a previous HER process, was reactivated and regenerated for the next run, where partially oxidized Te was found, surprisingly, to perform better than its nonoxidized state. After 10 consecutive deactivation-regeneration cycles over 480 h, the Te-ACs@NC retained 85% of its initial catalytic activity. Theoretical studies suggest that local oxidation modulates the electronic distribution within individual Te clusters to optimize the adsorption energy of water molecules and reduce dissociation energy. This study provides fundamental insights into the rarely explored metalloid cluster catalysts during deactivation and regeneration and will assist in the future design and development of supported catalysts with high activity and long durability.

In Situ Measurement of Adhesion for Multimetallic Nanoparticles

The adhesion of nanoparticles to their supports is key to their performance and stability. However, scientific advances in this area have been hampered by the difficulty of experimentally probing adhesion. To date, only a single technique has been developed that can directly measure nanoparticle adhesion, and this technique is inherently limited to monometallic systems. We present a versatile technique for the direct measurement of adhesion for bimetallic nanoparticle systems. This technique combines the spatial resolution of transmission electron microscopy with the force resolution of an atomic force microscope to probe individual, well-characterized nanoparticles. A first study of supported bimetallic nanoparticles provides new insights into the complex impact of alloying on nanoparticle adhesion, explained by charge transfer between constituent metals. The new experimental technique is readily extensible to study other multimetallic nanoparticle systems, including the effects of particle size, shape, and orientation, thus enabling advances in our understanding of nanoparticle physics.

Deactivation Mechanism and Mitigation Strategies of Single-Atom Site Electrocatalysts

Single-atom site electrocatalysts (SACs), with maximum atom efficiency, fine-tuned coordination structure, and exceptional reactivity toward catalysis, energy, and environmental purification, have become the emerging frontier in recent decade. Along with significant breakthroughs in activity and selectivity, the limited stability and durability of SACs are often underemphasized, posing a grand challenge in meeting the practical requirements. One pivotal obstacle to the construction of highly stable SACs is the heavy reliance on empirical rather than rational design methods. A comprehensive review is urgently needed to offer a concise overview of the recent progress in SACs stability/durability, encompassing both deactivation mechanism and mitigation strategies. Herein, this review first critically summarizes the SACs degradation mechanism and induction factors at the atomic-, meso- and nanoscale, mainly based on but not limited to oxygen reduction reaction. Subsequently, potential stability/durability improvement strategies by tuning catalyst composition, structure, morphology and surface are delineated, including construction of robust substrate and metal-support interaction, optimization of active site stability, fabrication of porosity and surface modification. Finally, the challenges and prospects for robust SACs are discussed. This review facilitates the fundamental understanding of catalyst degradation mechanism and provides efficient design principles aimed at overcoming deactivation difficulties for SACs and beyond.

Platinum-Nickel Oxide Cluster-Cluster Heterostructure Enabling Fast Hydrogen Evolution for Anion Exchange Membrane Water Electrolyzers

Carbon black has been extensively employed as the support for noble metal catalysts for electrocatalysis applications. However, the nearly catalytic inertness and weak interaction with metal species of carbon black are two major obstacles that hinder the further improvement of the catalytic performance. Herein, we report a surface functionalization strategy by decorating transition metal oxide clusters on the commercial carbon black to offer specific catalytic activity and enhanced interaction with metal species. In the case of NiOx cluster-decorated carbon black, a strongly coupled cluster-cluster heterostructure consisting of Pt clusters and NiOx clusters (Pt-NiOx/C) is formed and delivers greatly enhanced alkaline hydrogen evolution kinetics. The NiOx clusters can not only accelerate the hydrogen evolution process as the co-catalyst, but also optimize the adsorption of H intermediates on Pt and stabilize the Pt clusters. Notably, the anion exchange membrane water electrolyzer with Pt-NiOx/C as the cathode catalyst (with a loading of only 50 μgPt cm-2) delivers the most competitive electrochemical performance reported to date, requiring only 1.90 V to reach a current density of 2 A cm-2. The results demonstrate the significance of surface functionalization of carbonaceous supports toward the development of advanced electrocatalysts.

A multi-modal transformer for predicting global minimum adsorption energy

The fast assessment of the global minimum adsorption energy (GMAE) between catalyst surfaces and adsorbates is crucial for large-scale catalyst screening. However, multiple adsorption sites and numerous possible adsorption configurations for each surface/adsorbate combination make it prohibitively expensive to calculate the GMAE through density functional theory (DFT). Thus, we designed a multi-modal transformer called AdsMT to rapidly predict the GMAE based on surface graphs and adsorbate feature vectors without site-binding information. The AdsMT model effectively captures the intricate relationships between adsorbates and surface atoms through the cross-attention mechanism, hence avoiding the enumeration of adsorption configurations. Three diverse benchmark datasets were introduced, providing a foundation for further research on the challenging GMAE prediction task. Our AdsMT framework demonstrates excellent performance by adopting the tailored graph encoder and transfer learning, achieving mean absolute errors of 0.09, 0.14, and 0.39 eV, respectively. Beyond GMAE prediction, AdsMT's cross-attention scores showcase the interpretable potential to identify the most energetically favorable adsorption sites. Additionally, uncertainty quantification was integrated into our models to enhance the trustworthiness of the predictions.

Isolated Metal Centers Activate Small Molecule Electrooxidation: Mechanisms and Applications

Electrochemical oxidation of small molecules shows great promise to substitute oxygen evolution reaction (OER) or hydrogen oxidation reaction (HOR) to enhance reaction kinetics and reduce energy consumption, as well as produce high-valued chemicals or serve as fuels. For these oxidation reactions, high-valence metal sites generated at oxidative potentials are typically considered as active sites to trigger the oxidation process of small molecules. Isolated atom site catalysts (IASCs) have been developed as an ideal system to precisely regulate the oxidation state and coordination environment of single-metal centers, and thus optimize their catalytic property. The isolated metal sites in IASCs inherently possess a positive oxidation state, and can be more readily produce homogeneous high-valence active sites under oxidative potentials than their nanoparticle counterparts. Meanwhile, IASCs merely possess the isolated metal centers but lack ensemble metal sites, which can alter the adsorption configurations of small molecules as compared with nanoparticle counterparts, and thus induce various reaction pathways and mechanisms to change product selectivity. More importantly, the construction of isolated metal centers is discovered to limit metal d-electron back donation to CO 2p* orbital and reduce the overly strong adsorption of CO on ensemble metal sites, which resolve the CO poisoning problems in most small molecules electro-oxidation reactions and thus improve catalytic stability. Based on these advantages of IASCs in the fields of electrochemical oxidation of small molecules, this review summarizes recent developments and advancements in IASCs in small molecules electro-oxidation reactions, focusing on anodic HOR in fuel cells and OER in electrolytic cells as well as their alternative reactions, such as formic acid/methanol/ethanol/glycerol/urea/5-hydroxymethylfurfural (HMF) oxidation reactions as key reactions. The catalytic merits of different oxidation reactions and the decoding of structure-activity relationships are specifically discussed to guide the precise design and structural regulation of IASCs from the perspective of a comprehensive reaction mechanism. Finally, future prospects and challenges are put forward, aiming to motivate more application possibilities for diverse functional IASCs.

Perovskite Type ABO3 Oxides in Photocatalysis, Electrocatalysis, and Solid Oxide Fuel Cells: State of the Art and Future Prospects

Since photocatalytic and electrocatalytic technologies are crucial for tackling the energy and environmental challenges, significant efforts have been put into exploring advanced catalysts. Among them, perovskite type ABO3 oxides show great promising catalytic activities because of their flexible physical and chemical properties. In this review, the fundamentals and recent progress in the synthesis of perovskite type ABO3 oxides are considered. We describe the mechanisms for electrocatalytic oxygen evolution reactions (OER), oxygen reduction reactions (ORR), hydrogen evolution reactions (HER), nitrogen reduction reactions (NRR), carbon dioxide reduction reactions (CO2RR), and metal-air batteries in details. Furthermore, the photocatalytic water splitting, CO2 conversion, pollutant degradation, and nitrogen fixation are reviewed as well. We also stress the applications of perovskite type ABO3 oxides in solid oxide fuel cells (SOFs). Finally, the optimization of perovskite type ABO3 oxides for applications in various fields and an outlook on the current and future challenges are depicted. The aim of this review is to present a broad overview of the recent advancements in the development of perovskite type ABO3 oxides-based catalysts and their applications in energy conversion and environmental remediation, as well as to present a roadmap for future development in these hot research areas.

Non-negligible Organic Carbon Transfer during Organic Pollutant Degradation Processes by Advanced Oxidation Technologies

Heterogeneous Fenton and Fenton-like reactions, as one of the significant development directions of advanced oxidation processes (AOPs), still have some limitations that hinder their large-scale practical application. Organic carbon transfer processes (OCTPs) in AOPs including direct oxidation transfer processes (DOTPs) and changes in the solubility of pollutant reaction intermediates can lead to a significant accumulation of organics on the catalyst. The accumulation of organics severely impacts the sustainability of the catalyst and may lead to erroneous guidance about the mineralization rate of the reaction system. This perspective provides a comprehensive overview of recent research on OCTPs and presents new viewpoints and research directions for heterogeneous AOPs.

Dynamically Stable Cu0Cuδ+ Pair Sites Based on In Situ-Exsolved Cu Nanoclusters on CaCO3 for Efficient CO2 Electroreduction

Copper-based catalysts are the choice for producing multi-carbon products (C2+) during CO2 electroreduction (CO2RR), where the Cu0Cuδ+ pair sites are proposed to be synergistic hotspots for C-C coupling. Maintaining their dynamic stability requires precise control over electron affinity and anion vacancy formation energy, posing significant challenges. Here, we present an in situ reconstruction strategy to create dynamically stable Cu0Cu0.18+OCa motifs at the interface of exsolved Cu nanoclusters and CaCO3 nanospheres (Cu/CaCO3). In situ XAFS analysis confirmed the low-valency state of Cuδ+ during CO2RR. DFT calculations demonstrated that the nanocluster size arises from the balance between metal-support interactions and Cu-Cu cohesive energy, while the dynamic stability of rich interfacial Cuδ+ sites is attributed to their low electron affinity and high CO3 2- vacancy formation energy, which collectively contribute to reduced reducibility. The transformed Cu/CaCO3 exhibits an impressive C2+ Faradaic efficiency of 83.7 % at a partial current density of 393 mA cm-2, facilitated by adsorption of *CO with varying electronegativity at heterogeneous copper sites that lowers the C-C coupling energy barrier. Our findings establish insoluble carbonate as an effective anion pairing for Cu0Cuδ+ sites, highlighting the effectiveness of the in situ reconstitution strategy in producing a high density of dynamically stable Cu0Cuδ+ pair sites.

Improving the Methane Oxidation by Self-Adaptive Optimization of Liquid-Metal Catalysts

Methane (CH4), a major greenhouse gas and abundant carbon resource, presents significant challenges in catalysis due to its high symmetry and thermodynamic stability, which tend to cause over-oxidation to CO2. Traditional catalysts require high temperatures and pressures to facilitate CH4 conversion, constrained by their rigid structures which lack the flexibility needed for optimizing complex reaction steps. This study introduces a novel Cu embedded liquid metal catalyst (Cu-LMC) based on gallium alloys, characterized by dynamic, self-adaptive structures that provide enhanced catalytic performance and selectivity. Our findings reveal that Cu-LMC achieves a high methane conversion to methanol yield (5.9 mol⋅gCu -1⋅h-1) with a selectivity of 82 %. The results show that mild surface oxidation significantly boosts the catalytic performance of Cu-LMC by increasing active copper sites through the formation of a Cu-O-Ga configuration while preserving the catalyst's structural flexibility. In situ X-ray Photoelectron Spectroscopy (XPS) and X-ray Absorption Fine Structure (XAFS) analyses, along with ab initio Molecular Dynamics (AIMD) simulations, demonstrate that the Cu-LMC enables self-adaptive structural adjustments that lower methanol desorption energy and increase the energy barrier for by-product formation, optimizing the overall methane conversion process. The results underscore the importance of designing catalysts with dynamic and adaptable structures to overcome traditional limitations and improve efficiency in catalytic reactions.

Ultrafine metal nanoparticles isolated on oxide nano-islands as exceptional sintering-resistant catalysts

Ultrafine nanoparticles (NPs) have attracted extensive research interest, especially in heterogeneous catalysis. However, the inherent sintering propensity of NPs has been a major obstacle to their catalytic stability. Here we report an isolation strategy to preserve highly dispersed ultrafine NPs under extremely harsh conditions. Oxide nano-islands were grafted between the catalyst support and metal NPs, serving as a general approach by following a charge attraction principle. Specifically, LaOx nano-islands were ideally suited for stabilizing Ru NPs among the synthetic library, exhibiting strong adhesion to minimize the chemical potential and disconnect the sintering path. Thus, ultrafine Ru NPs in Ru/LaOx-SiO2 were isolated, maintaining a mean size of 1.4 nm in CO- and H2-rich atmosphere during efficient catalysis for methane dry reforming at 800 °C for 400 h. This isolation strategy has proved effective for many other metals on various supports, paving a practical way for the design of sintering-resistant catalysts.

Precisely Tailoring the Second Coordination Sphere of a Cobalt Single-Atom Catalyst for Selective Hydrogenation of Halogenated Nitroarenes

The development of highly efficient and cost-effective nonprecious metal catalysts for the selective hydrogenation of halogenated nitroarenes is very appealing yet challenging. Here, we demonstrate that the hydrogenation activity and selectivity of Co single-atom catalyst (SAC) can be tuned by tailoring the structure of second coordination sphere via P doping. As revealed by synchrotron radiation-based X-ray absorption spectroscopy characterizations, such a P doping on N-coordinated Co SAC results in the unsymmetric Co-N4P1 coordination structure. With a combination of experimental characterizations and theoretical simulations, we find that tailoring the second coordination sphere can greatly improve H2 dissociation and product desorption. As a result, the Co-N4P1 SAC exhibits superior activity, selectivity and stability for the hydrogenation of halogenated nitroarenes to corresponding amines (20 examples, >99 % yields) at 80 °C under 0.5 MPa H2 pressure, significantly outperforming most heterogeneous catalysts reported in the literature. We expect that this work opens a new avenue for the design of highly efficient nonprecious metal SACs for important hydrogenation reactions.

Double Confinement Design to Access Highly Stable Intermetallic Nanoparticles for Fuel Cells

Maintaining the stability of low Pt catalysts during prolonged operation of proton exchange membrane fuel cells (PEMFCs) remains a substantial challenge. Here, a double confinement design is presented to significantly improve the stability of intermetallic nanoparticles while maintaining their high catalytic activity toward PEMFCs. First, a carbon shell is coated on the surface of nanoparticles to form carbon confinement. Second, O2 is introduced during the annealing process to selectively etch the carbon shell to expose the active surface, and to induce the segregation of surface transition metals to form Pt-skin confinement. Overall, the intermetallic nanoparticles are protected by carbon confinement and Pt-skin confinement to withstand the harsh environment of PEMFCs. Typically, the double confined Pt1Co1 catalyst exhibits an exceptional mass activity of 1.45 A mgPt -1 at 0.9 V in PEMFCs tests, with only a 17.3% decay after 30 000 cycles and no observed structure changes, outperforming most reported PtCo catalysts and DOE 2025 targets. Furthermore, the carbon confinement proportion can be controlled by varying the thickness of the coated carbon shell, and this strategy is also applicable to the synthesis of double-confined Pt1Fe1 and Pt1Cu1 intermetallic nanoparticles.

Electrocatalytic Biomass Oxidation via Acid-Induced In Situ Surface Reconstruction of Multivalent State Coexistence in Metal Foams

Electrocatalytic biomass conversion offers a sustainable route for producing organic chemicals, with electrode design being critical to determining reaction rate and selectivity. Herein, a prediction-synthesis-validation approach is developed to obtain electrodes for precise biomass conversion, where the coexistence of multiple metal valence states leads to excellent electrocatalytic performance due to the activated redox cycle. This promising integrated foam electrode is developed via acid-induced surface reconstruction to in situ generate highly active metal (oxy)hydroxide or oxide (MOxHy or MOx) species on inert foam electrodes, facilitating the electrooxidation of 5-hydroxymethylfurfural (5-HMF) to 2,5-furandicarboxylic acid (FDCA). Taking nickel foam electrode as an example, the resulting NiOxHy/Ni catalyst, featuring the coexistence of multivalent states of Ni, exhibits remarkable activity and stability with a FDCA yields over 95% and a Faradaic efficiency of 99%. In situ Raman spectroscopy and theoretical analysis reveal an Ni(OH)2/NiOOH-mediated indirect pathway, with the chemical oxidation of 5-HMF as the rate-limiting step. Furthermore, this in situ surface reconstruction approach can be extended to various metal foams (Fe, Cu, FeNi, and NiMo), offering a mild, scalable, and cost-effective method for preparing potent foam catalysts. This approach promotes a circular economy by enabling more efficient biomass conversion processes, providing a versatile and impactful tool in the field of sustainable catalysis.

Oxygen Vacancies Promote Formaldehyde Base-Free Reforming into Hydrogen over Cu Doping-Induced Cu-CuxZn1-xO Heterointerfaces

Element doping is a viable strategy to regulate the metal-support interface for enhancing the catalytic performance of supported metal catalysts. Herein, Cu/ZnO:Cu-TH catalysts are prepared by immobilizing Cu nanoparticles (NPs) on ZnO nanorods featuring an adjustable oxygen vacancy, in which partial Cu atoms at the Cu-ZnO interface are incorporated into the ZnO lattice to form CuxZn1-xO species. Such Cu atom doping induces the creation of distinctive Cu-CuxZn1-xO interface sites and optimizes electron transfer from ZnO to Cu NPs, thereby achieving intermediate activation and ultimately endowing the catalyst with superior performance in reforming alkali-free formaldehyde (HCHO) into hydrogen at low temperatures. The Cu-CuxZn1-xO interface sites serve as pivotal centers for HCHO reforming, where the Cu sites and CuxZn1-xO sites selectively engage in the cleavage of C-H bonds in HCHO and O-H bonds in H2O, respectively. Meanwhile, the presence of oxygen vacancies bolsters the Cu-CuxZn1-xO sites in enhancing the adsorption of HCHO and H2O, further improving the activity. The Cu/ZnO:Cu-450H catalyst, distinguished by abundant Cu-CuxZn1-xO sites and a high concentration of oxygen vacancies, demonstrates optimal activity with TOF values of 16.9 and 72.4 h-1 under anaerobic and aerobic conditions, respectively, which are 8.9 and 29.0 times higher than those of the Cu/ZnO-450N catalyst, which lacks doped Cu atoms and oxygen vacancies.

Finely Tailoring Metal-Support Interactions via Transient High-Temperature Pulses

Metal-support interactions (MSI) play a crucial role in enhancing the catalytic activity and stability of metal catalysts by establishing a stable metal-oxide interface. However, precisely controlling MSI at the atomic scale remains a significant challenge, as how to construct an optimal MSI is still not fully understood: Both insufficient and excessive MSI showed inferior catalytic performance. In this study, we propose finely tuning MSI using temporal-precise transient high-temperature pulse heating. Using Pt/CeO2 as a model system, we systematically investigate how variations in pulse duration and atmosphere influence the reconstruction of the metal-support interface and MSIs. This leads to the formation of two distinct types of MSI: (1) strong MSI (SMSI, Pt@CeO2) and (2) reactive MSI (RMSI, Pt5Ce@CeO2), each with unique compositions, structures, and electrochemical behaviors. Notably, Pt5Ce@CeO2 with RMSI exhibits remarkable catalytic performance in the alkaline hydrogen evolution, showing an overpotential of -29 mV and stable operation for over 300 h at -10 mA·cm-2. Theoretical studies reveal that alloying Pt with Ce to form Pt5Ce modifies the electronic structure of Pt, shifting the d-band center to optimize the adsorption and dissociation of intermediates, thereby reducing the reaction energy barrier. Moreover, the intimate interaction of Pt5Ce with CeO2 further improves the activity and stability. Our strategy enables precise, stepwise, and controllable regulation of MSIs, providing insights for the development of highly efficient and durable heterostructured catalysts with optimal MSI for a wide range of catalytic applications.

Wireless Thermochromic Platform Based on Au/SiO2 Photonic Crystals for Operando Monitoring of Catalyst Sintering with Machine Learning

Operando monitoring of the catalyst sinter-degree during reactions is essential for achieving a stable, safe, and efficient chemical engineering process. This work introduces a wireless thermochromic platform that utilizes machine learning to correlate color changes with the sinter-degree of catalysts and to identify hot spots during chemical reactions. After being decorated with sub-2 nm Au clusters, SiO2 photonic crystals were endowed with a distinct color change from the inherent blue hue of SiO2 photonic crystals to the distinctive red shade associated with Au clusters, due to the gradual growth of Au clusters over a wide temperature range from 25 to 900 °C. With the assistance of an artificial neural network, a robust correlation was established between the observed color change and the sinter-degree of Au species. After training, the smart Au/SiO2 catalyst achieved self-visualization for the sinter-degree of Au species within 12.4 μm × 12.4 μm, during CO oxidation. Moreover, an intelligent noninvasive platform can be constructed by patterning Au/SiO2 photonic crystals into quick response codes, for real-time monitoring of temperature distribution at a micro-region scale (208 μm × 208 μm) within 5 ms during chemical reactions. The Au/SiO2 thermochromic platform enables wireless data transmission and facilitates the programmable warning of abnormal hot spots in reactors. This work serves as a technical reserve for future research on the development of advanced catalysts and offers further insight into the chemical engineering process.

Determining the Magnetic Status of Active Sites on Nanocatalysts

Identifying the atomic structure and chemical composition of active sites on nanocatalysts has been a long pursuit in heterogeneous catalysis. Yet, determining the magnetic structure of a well-defined active site is even more challenging. However, explicit morphology and reaction temperature have not been considered in identifying the magnetic behaviors of the nanocatalysts, especially in theoretical studies. Herein, we determined the magnetic status of nanoscale catalysts at finite temperatures by using atomistic spin models. The size dependence of the Curie point and the magnetic premelting have been discussed, indicating that the magnetic properties over a localized active center can greatly differ from the bulk. Therefore, the magnetic phase transitions and its concomitant magneto-catalytic effect can be induced at a considerably low temperature. Our analysis demonstrated that an 8 nm cobalt-based core-shell nanoparticle can achieve the optimal magnetization with Sabatier optimal activity for ammonia synthesis at 523 K, which is in accord with the reaction condition of the Haber-Bosch process. We believe our findings elucidate the importance of determining the localized magnetic configuration for active sites. Furthermore, including this unexcavated dimension in the dynamical simulations of the catalytic process can provide us with a more complete and comprehensive understanding of the reaction mechanism under working conditions.

Strong Metal-Support Interaction between Pt and TiO2 over High-Temperature CO2 Hydrogenation

The catalytic activities and stability of oxide-supported metal catalysts are significantly affected by metal-support interactions (MSI) between oxidic supports and supported metals. The surface properties of the support, such as its phase and defects, are crucial in MSI, including both the strong metal-support interaction (SMSI) and electronic metal-support interaction (EMSI). In this study, modulation of SMSI was achieved on rutile-supported Pt nanoparticles (NP) over high-temperature CO2 hydrogenation. The encapsulation of Pt NP surfaces with TiO2-x overlayers is precisely controlled by the defects. It is found that oxygen vacancy defects significantly enhance the catalytic stability of Pt/rutile under high-temperature reverse water-gas shift (RWGS) reaction by inhibiting the occurrence of SMSI. Pt/rutile with oxygen vacancies achieves a 301 molCO ⋅ gM -1 ⋅ h-1 space time yield and considerably catalytic stability (decreased by 8 %) at 800 °C over 100 h time-on-stream. Density functional theory (DFT) calculations suggest that the adsorption capacity of Pt NP on the rutile overlayer can be reduced by increasing electron density. Experimental results combined with DFT calculations show that electron transfer from Pt NP to rutile is reduced by the oxygen vacancy defects on Pt/R, preserving the metallic nature of Pt species during CO2 hydrogenation, thereby preventing the formation of SMSI.

Sabatier Optimal of Mn-N4 Single Atom Catalysts for Selective Oxidative Desulfurization

Understanding the relationship of competitive adsorption between reactants is the prerequisite for high activity and selectivity in heterogeneous catalysis, especially the difference between the adsorption energies (Eads) of two reactive intermediates in Langmuir-Hinshelwood (L-H) models. Using oxidative dehydrogenation of hydrogen sulfide (H2S-ODH) as a probe, we develop various metal single atoms on nitrogen-doped carbon (M-NDC) catalysts for controlling Eads-H2S, Eads-O2 and investigating the difference in activity and selectivity. Combining theoretical and experimental results, a Sabatier relationship between the catalytic performance and Eads-O2/Eads-H2S emerges. Mn-NDC as the optimal catalyst shows excellent H2S conversion (>90 %) and sulfur selectivity (>90 %) in a wide range of O2 concentrations over 100 h. Such a high-efficiency performance is attributed to appropriate Eads-H2S and Eads-O2 on Mn-N4 sites, boosting redox cycle between Mn2+ and Mn3+, as well as preferential formation of sulfur. This work provides a fundamental guidance for designing Sabatier optimal catalysts in L-H models.

Enhancing Li Deposition Behavior through Valence Gradient-Assisted Iron Layer

Uncontrolled lithium (Li) dendrite formation presents major safety risks and challenges in the Li host design. A novel approach is introduced, using a valence gradient in iron nanoparticles (Fe0, Fe2+, Fe3+) to stabilize the anodes. An Fe0 component, with fast Li diffusion, ensures a steady supply of Li to Fe2+ and Fe3+ components, which have slower Li diffusion. This coordinated interplay between fast and slow diffusion uniformizes Li deposition near the substrate, effectively reducing the rate of dendrite growth. The as-prepared framework demonstrates uniform Li plating with a minimal hysteresis voltage after extensive cycling for 1200 h in symmetric cells. Integrated into a full cell with LiFePO4, it demonstrates outstanding cycling stability for almost 950 cycles with a capacity of 92.2 mA h g-1 at 1C with an ultralow N/P ratio of 1.19. This valence gradient design strategy broadens the design potential for transition-metal compounds in regulating Li deposition by mitigating interfacial Li+ behavior.

Lewis Acid Sites Assisted PtCu/CeO2-C Enabling High-Performance for Oxygen Reduction

Improvement in the durable and active low-Pt nanocatalysts for oxygen reduction reaction (ORR) is the essential target for clean energy. Herein, an efficient CeO2 supported PtCu alloy catalyst (PtCu/CeO2-C) for ORR in acid media is developed. The CeO2 support can effectively anchor the PtCu particles and inhibit their migration during the long-life cycling, which is beneficial to the catalytic performance. According to the electrochemical experiments, the specific and mass activities of PtCu/CeO2-C are 1.09 mA cm-2 and 0.49 A mgPt -1 at 0.9 V, which are 9.9 and 6.1 times as large as that of Pt/C, demonstrating its outstanding ORR activities in acid media. Moreover, the theoretical studies confirm that oxygen vacancies (VO) as Lewis acid sites can facilitate the adsorption and dissociation of O2, regulate the electronic structure of Pt, and thus endow PtCu/CeO2-C with an efficient 4-electron ORR pathway. The results suggest that the rational design of supported Pt-based catalysts is of great significance for efficient ORR reaction.

Recent Progress in Balancing the Activity, Durability, and Low Ir Content for Ir-Based Oxygen Evolution Reaction Electrocatalysts in Acidic Media

Proton exchange membrane (PEM) electrolysis faces challenges associated with high overpotential and acidic environments, which pose significant hurdles in developing highly active and durable electrocatalysts for the oxygen evolution reaction (OER). Ir-based nanomaterials are considered promising OER catalysts for PEM due to their favorable intrinsic activity and stability under acidic conditions. However, their high cost and limited availability pose significant limitations. Consequently, numerous studies have emerged aimed at reducing iridium content while maintaining high activity and durability. Furthermore, the research on the OER mechanism of Ir-based catalysts has garnered widespread attention due to differing views among researchers. The recent progress in balancing activity, durability, and low iridium content in Ir-based catalysts is summarized in this review, with a particular focus on the effects of catalyst morphology, heteroatom doping, substrate introduction, and novel structure development on catalyst performance from four perspectives. Additionally, the recent mechanistic studies on Ir-based OER catalysts is discussed, and both theoretical and experimental approaches is summarized to elucidate the Ir-based OER mechanism. Finally, the perspectives on the challenges and future developments of Ir-based OER catalysts is presented.

Metal nanoparticles encapsulation within multi-shell spongy-core porous microspheres for efficient tandem catalysis

The "one-pot" cascade process involves multiple catalytic conversions followed by a single workup stage. This method has the capability to optimize catalytic efficiency by reducing chemical processes. The key to achieving cascade reactions lies in designing cascade catalysts with well-dispersed, stably immobilized, and accessible noble metal nanoparticles for multiple catalytic conversions. This work presents a strategy for creating long-lasting cascade catalysts by encapsulating Ru and Pd nanoparticles within multi-shell spongy-core porous microspheres (MS-SC-PMs). This cascade catalyst strategy enables the continuous hydrogenation of nitrobenzene to aniline and further to cyclohexylamine, demonstrating both high selectivity and conversion rates. Notably, this approach overcomes the typical challenges associated with noble metal nanoparticles, such as poor stability and recyclability, as it maintains its performance over ten consecutive cycles. Additionally, the MS-SC-PMs have the versatility to encapsulate various metal nanoparticles, providing catalytic versatility, scalability, and a promising avenue for designing long-lasting catalysts loaded with nanoparticles.

Advanced Ruthenium-Based Electrocatalysts for NOx Reduction to Ammonia

Ammonia (NH3) is widely recognized as a crucial raw material for nitrogen-based fertilizer production and eco-friendly hydrogen-rich fuels. Currently, the Haber-Bosch process still dominates the worldwide industrial NH3 production, which consumes substantial energy and contributes to enormous CO2 emission. As an alternative NH3 synthesis route, electrocatalytic reduction of NOx species (NO3 -, NO2 -, and NO) to NH3 has gained considerable attention due to its advantages such as flexibility, low power consumption, sustainability, and environmental friendliness. This review timely summarizes an updated and critical survey of mechanism, design, and application of Ru-based electrocatalysts for NOx reduction. First, the reason why the Ru-based catalysts are good choice for NOx reduction to NH3 is presented. Second, the reaction mechanism of NOx over Ru-based materials is succinctly summarized. Third, several typical in situ characterization techniques, theoretical calculations, and kinetics analysis are examined. Subsequently, the construction of each classification of the Ru-based electrocatalysts according to the size of particles and compositions is critically reviewed. Apart from these, examples are given on the applications in the production of valuable chemicals and Zn-NOx batteries. Finally, this review concludes with a summary highlighting the main practical challenges relevant to selectivity and efficiency in the broad range of NOx concentrations and the high currents, as well as the critical perspectives on the fronter of this exciting research area.

In Situ Construction of a Porous Nanotrap: A Pathway for Catalyst Performance Optimization

Supported noble metal catalysts have a high catalytic activity and selectivity. However, fast surface reconstruction and sintering of noble metal particles during a high-temperature reaction process pose a major challenge to the stability of the catalysts. In this study, sinter-resistant supported noble metal catalysts were prepared by constructing an oxide nanotrap. Pt/Al2O3 was used as a research paradigm. Dopamine was applied as a structure-directing agent and pore-forming agent to form a porous CeO2 overlay on the surface of Pt/Al2O3 and encapsulate Pt nanoparticles. Due to the confinement of CeO2 and its interaction with Pt, the modified Pt/Al2O3@CeO2 exhibits superior catalytic activity and antisintering stability. This method can be extended to other supported catalyst systems.

Dynamically Confined Active Silver Nanoclusters with Ultrawide Operating Temperature Window in CO oxidation

Supported metal nanoclusters are often highly active in many catalytic reactions but less stable particularly under harsh reaction conditions. Here, we demonstrate that this activity-stability trade-off can be efficiently broken through rational design of surrounding microenvironment of the supported nanocatalyst including gas adsorbate overlayer and underneath support surface chemistry. Our studies reveal that chemisorbed oxygen species on Ag surface and surface hydroxyl groups on oxide support, which are dynamically consumed during reaction but sustained by reaction environment (O2 and H2O vapor), drive spontaneous redispersion of Ag particles and stabilization of highly active Ag nanoclusters. Such a dynamic confinement effect from gas-catalyst-support interaction enables the Ag nanoclusters to exhibit complete catalytic oxidation of CO over a wide temperature window of 25-500 °C under dry conditions and 200-800 °C under wet conditions as well as remarkable stability at 300 °C over 1000 h.

Precise Regulation of In Situ Exsolution Components of Nanoparticles for Constructing Active Interfaces toward Carbon Dioxide Reduction

Metal nanocatalysts supported on oxide scaffolds have been widely used in energy storage and conversion reactions. So far, the main research is still focused on the growth, density, size, and activity enhancement of exsolved nanoparticles (NPs). However, the lack of precise regulation of the type and composition of NPs elements under reduction conditions has restricted the architectural development of in situ exsolution systems. Herein, we propose a strategy to attain a regulated distribution of exsolved transition metals (Cu, Ni, and Fe) on Sr2Fe1.2Ni0.2Cu0.2Mo0.4O6-δ medium-entropy perovskite oxides by varying the oxygen partial pressure (pO2) gradient in the mixture. At 800 °C, the unitary Cu, binary Cu-Ni, and ternary Cu-Ni-Fe NPs are exsolved as pO2 decreases from high to low. Combining experimental and theoretical simulations, we further corroborate that solid oxide electrolysis cells with ternary alloy clusters at the CNF@SFO interface exhibit superior CO2 electrolytic performance. Our results provide tailored strategies for nanostructures and nanointerfaces for studying metal oxide exsolution systems, including fuel electrode materials.

C60 Fullerene-Induced Reduction of Metal Ions: Synthesis of C60-Metal Cluster Heterostructures with High Electrocatalytic Hydrogen-Evolution Performance

Metal clusters, due to their small dimensions, contain a high proportion of surface atoms, thus possessing a significantly improved catalytic activity compared with their bulk counterparts and nanoparticles. Defective and modified carbon supports are effective in stabilizing metal clusters, however, the synthesis of isolated metal clusters still requires multiple steps and harsh conditions. Herein, we develop a C60 fullerene-driven spontaneous metal deposition process, where C60 serves as both a reductant and an anchor, to achieve uniform metal (Rh, Ir, Pt, Pd, Au and Ru) clusters without the need for any defects or functional groups on C60. Density functional theory calculations reveal that C60 possesses multiple strong metal adsorption sites, which favors stable and uniform deposition of metal atoms. In addition, owing to the electron-withdrawing properties of C60, the electronic structures of metal clusters are effectively regulated, not only optimizing the adsorption behavior of reaction intermediates but also accelerating the kinetics of hydrogen evolution reaction. The synthesized Ru/C60-300 exhibits remarkable performance for hydrogen evolution in an alkaline condition. This study demonstrates a facile and efficient method for synthesizing effective fullerene-supported metal cluster catalysts without any pretreatment and additional reducing agent.

Strong Metal-Support Interaction Triggered by Molten Salts

Strong metal-support interaction (SMSI) plays a vital role in tuning the geometric and electronic structures of metal species. Generally, a high-temperature treatment (>500 °C) in reducing atmosphere is required for constructing SMSI, which may induce the sintering of metal species. Herein, we use molten salts as the reaction media to trigger the formation of high-intensity SMSI at reduced temperatures. The strong ionic polarization of the molten salt promotes the breakage of Ti-O bonds in the TiO2 support, and hence decreases the energy barrier for the formation of interfacial bonds. Consequently, a high-intensity SMSI state is achieved in TiO2 supported Ir nanoclusters, evidenced by a large number of Ir-Ti bonds at the interface, at a low temperature of 350 °C. Moreover, this method is applicable for triggering SMSI in various supported metal catalysts with different oxide supports including CeO2 and SnO2. This newly developed SMSI construction methodology opens a new avenue and holds significant potential for engineering advanced supported metal catalysts toward a broad range of applications.

Asymmetric Coupled Binuclear-Site Catalysts for Low-Temperature Selective Acetylene Semi-Hydrogenation

Heterogeneous metal catalysts with bifunctional active sites are widely used in chemical industries. Although their improvement process is typically based on trial-and-error, it is hindered by the lack of model catalysts. Herein, we report an effective vacancy-pair capturing strategy to fabricate 12 heterogeneous binuclear-site catalysts (HBSCs) comprising combinations of transition metals on titania. During the synthesis of these HBSCs, proton-passivation treatment and step-by-step electrostatic anchorage enabled the suppression of single-atom formation and the successive capture of two target metal cations on the titanium-oxygen vacancy-pair site. Additionally, during acetylene hydrogenation at 20 °C, the HBSCs (e.g., Pt1Pd1-TiO2) consistently generated more than two times the ethylene produced by their single-atom counterparts (e.g., Pd1-TiO2). Furthermore, the Pt1Pd1 binuclear sites in Pt1Pd1-TiO2 were demonstrated to catalyze C2H2 hydrogenation via a bifunctional active-site mechanism: initially C2H2 chemisorb on the Pt1 site, then H2 dissociates and migrates from Pd1 to Pt1, and finally hydrogenation occurs at the Pt1-Pd1 interface.

Synergize Strong and Reactive Metal-Support Interactions to Construct Sub-2 nm Metal Phosphide Cluster for Enhanced Selective Hydrogenation Activities

Strong metal-support interactions (SMSI) are crucial for stabilizing sub-2 nm metal sites, e.g. single atom (M1) or cluster (Mn). However, further optimizing sub-2 nm sites to break the activity-stability trade-off due to excessive interactions remains significant challenges. Accordingly, for the first time, we propose synergizing SMSI with reactive metal-support interactions (RMSI). Comprehensive characterization confirms that the SMSI stabilizes the metal and regulates the aggregation of Ni1 into Nin site within sub-2 nm. Meanwhile, RMSI modulates Nin through sufficiently activating P in the support and eventually generates sub-2 nm metal phosphide Ni2P cluster (Ni2Pn). The synergetic metal-support interactions triggered the adaptive coordination and electronic structure optimization of Ni2Pn, leading to the desired substrate adsorption-desorption kinetics. Consequently, the activity of Ni2Pn site greatly enhanced towards the selective hydrogenations of p-chloronitrobenzene and alkynyl alcohol. The formation rates of target products are up to 20.2 and 3.0 times greater than that of Ni1 and Nin site, respectively. This work may open a new direction for metal-support interactions and promote innovation and application of active sites below 2 nm.

Elementary Steps of Catalytic Reactions Occurring on Metallic Alloy Nanoparticles

Catalytic reactions running in an adsorbed overlayer on metallic alloy nanoparticles are of high interest in the context of applications in the chemical industry. The understanding of the corresponding kinetics is, however, still limited. One of the reasons of this state of the art is the interplay between adsorption and adsorbate-influenced segregation of metal atoms inside alloy nanoparticles. I scrutinize this interplay by using a generic field model of segregation and the mean-field approximation in order to describe adsorption, desorption, and elementary catalytic reactions. Under steady-state conditions, the segregation is demonstrated to be manifested in the change of the dependence of the activation energies of desorption or elementary reactions on coverage, and the sign of this change is positive. The effect of this change on the apparent reaction orders is briefly discussed as well.

Balanced Adsorption Toward Highly Selective Electrochemical Reduction of CO2 to Formate

Tin-based materials have been designed as potential catalysts for the electrochemical conversion of CO2 into a single product. However, such tin-based materials still face the challenges of unsatisfactory selectivity, because the rate-determining step is situated within the slow desorption step. In this work, a variety of tin-based materials are synthesized using the electrospinning technique in an effort to control the adsorption strength during electrochemical reduction, therefore improving the selectivity of CO2 reduction toward formate. The optimized SnS material exhibits moderate adsorption strength to *OCHO and *HCOOH, and the appropriate atomic distance of Sn-Sn maintained the balanced adsorption posture of both intermediate. Therefore, the rate-determining step can be shifted from the slow desorption of the *HCOOH step (Sn) to the first hydrogenation of the *OCHO species step (SnS). Due to this shift, the SnS/C electrode demonstrated excellent selectivity, with a Faradaic efficiency of 96% for the production of formate. A maximum current density of -12.5 mA cm-2 for formate is also achieved for a period of 33 h.

Sabatier Principle-Driven Single-Atom Coordination Engineering for Enhanced Fenton-Like Catalysis

Single-atom catalysts (SACs) are widely employed in Fenton-like catalysis, yet guidelines for their high-performance design remain elusive. The Sabatier principle provides guidance for the ideal catalyst with the highest activity. Herein, the study meticulously engineered a series of SACs featuring a broad distribution of d-band center through single-atom coordination engineering, facilitating a comprehensive exploration of the Sabatier relationship in Fenton-like catalysis. A volcanic correlation between d-band centers and catalytic activity is identified. Theoretical and experimental results show that moderate d-band center and peroxymonosulfate adsorption energy can lead to the lowest reaction barriers in the rate-determining step for generating singlet oxygen, thus enhancing catalytic efficiency toward the Sabatier optimum. As proof of concept, the Fe-N2O2/C catalyst demonstrates a degradation rate constant of 1.89 min-1, surpassing Fe-N4/C by 3.2 times and Fe-O4/C by 272 times. Moreover, Fe-N2O2/C shows exceptional tolerance to various environmental challenges, providing opportunities for achieving nearly eco-friendly pollutant degradation. The findings reveal how to use the Sabatier principle to guide the design of advanced SACs for efficient pollutant removal.

Dynamic phase transitions dictate the size effect and activity of supported gold catalysts

The landmark discovery of gold catalysts has aroused substantial interest in heterogeneous catalysis, yet the catalytic mechanism remains elusive. For carbon monoxide oxidation on gold nanoparticles (NPs) supported on ceria surfaces, it is widely believed that carbon monoxide adsorbs on the gold particles, while the reaction occurs at the gold/ceria interface. Here, we have investigated the dynamic changes of supported gold NPs with various sizes in a carbon monoxide oxidation atmosphere using deep potential molecular dynamics simulations. Our results reveal that the structure of tiny gold particles in carbon monoxide atmospheres becomes highly disordered and undergoes phase transition. Such a liquid-like structure provides massive reactive sites, enabling facile carbon monoxide oxidation on the solid-state gold NP rather than just at the gold/ceria interface. This result is further corroborated by catalytic experiments. This work sheds light on both the size effects and activity in noble metal catalysis and provides insights for the design of more effective nanocatalysts.

Asymmetric Polarization Modulation of d-p Hybridization-Enhanced Bidirectional Sulfur Redox Kinetics with Heteronuclear Dual-Atom Catalysts

Lithium sulfur batteries (LiSBs) represent a highly promising avenue for future energy storage systems, offering high energy density and eco-friendliness. However, the sluggish kinetics of the sulfur redox reaction (SRR) poses a significant challenge to their widespread applications. To tackle this challenge, we have developed an efficient heteronuclear dual-atom catalyst (hetero-DAC) that leverages surface charge polarization to enhance the asymmetric adsorption of sulfur intermediates. This study investigates how asymmetric electronic redistribution of CoFe DACs modulates the d-p orbital hybridization with sulfur intermediates, revealing the mechanisms of moderate adsorption dynamics with enhanced catalytic performance. The dynamic switching between mono and dual adsorption sites, enabled by the heteronuclear polarized configuration, fine-tunes the orbital hybridization, boosting the bidirectional rate-determining steps, that is, the solid-solid conversion of Li2S2 to Li2S and the reverse dissociation of Li2S. Consequently, the thus-designed CoFe DACs cathode delivers impressive rate performance, achieving a high initial specific capacity of 703.9 mA h g-1 at 3 C, with a negligible decay rate of only 0.031% over 1000 cycles, demonstrating sustained long-term cycling stability. This work bridges geometric configurations and electronic structures, elucidating the mechanisms of asymmetric trapping and conversion enabled by hetero-DACs and offering fresh perspectives for catalyst design in LiSBs and beyond.

Electrodegradation of nitrogenous pollutants in sewage: from reaction fundamentals to energy valorization applications

The excessive accumulation of nitrogen pollutants (mainly nitrate, nitrite, ammonia nitrogen, hydrazine, and urea) in water bodies seriously disrupts the natural nitrogen cycle and poses a significant threat to human life and health. Electrolysis is considered a promising method to degrade these nitrogenous pollutants in sewage, with the advantages of high efficiency, wide generality, easy operability, retrievability, and environmental friendliness. For particular energy devices, including metal-nitrate batteries, direct fuel cells, and hybrid water electrolyzers, the realization of energy valorization from sewage purification processes (e.g., valuable chemical generation, electricity output, and hydrogen production) becomes feasible. Despite the progress in the research on pollutant electrodegradation, the development of electrocatalysts with high activity, stability, and selectivity for pollutant removal, coupled with corresponding energy devices, remains a challenge. This review comprehensively provides advanced insights into the electrodegradation processes of nitrogenous pollutants and relevant energy valorization strategies, focusing on the reaction mechanisms, activity descriptors, electrocatalyst design, and actuated electrodes and operation parameters of tailored energy conversion devices. A feasibility analysis of electrodegradation on real wastewater samples from the perspective of pollutant concentration, pollutant accumulation, and electrolyte effects is provided. Challenges and prospects for the future development of electrodegradation systems are also discussed in detail to bridge the gap between experimental trials and commercial applications.