Alloying Pt into Ni partially amorphous for promoted alkaline hydrogen production

Platinum compounds constructing interface structure strategies for electrolysis hydrogen production

With the continuous growth of global energy demand, designing efficient hydrogen evolution reaction (HER) catalysts has become increasingly important. However, current interface structure synthesis strategies for platinum-based compounds are not yet adequate, limiting their application efficiency in hydrogen production. Therefore, this paper reviews a series of interface construction strategies, including the solvothermal method, gas-phase chemical method, heat treatment method, reduction method, electromagnetic synthesis method, electrochemical method, constructing heterojunctions method and constructing substrates method. These methods significantly enhance the overall performance of platinum-based catalysts by optimizing the interactions between the catalyst and support materials, improving electron transfer efficiency, and increasing the exposed area of active sites. Additionally, this paper introduces various interface structure strategies that can increase HER active sites, such as single-atom catalysts, diatomic catalysts, nanoparticles, nanowires, nanotubes, and porous structures. These nanostructures further enhance catalytic activity and stability by increasing the specific surface area and providing abundant reaction sites. Furthermore, this paper thoroughly elucidates the mechanisms of the HER in acidic and alkaline media, exploring the key factors for optimizing catalyst performance under different pH conditions. By understanding the HER mechanisms and combining advanced interface construction strategies with diverse nanostructure designs, researchers can better construct interfaces and design nanostructures, thereby developing platinum-based catalysts that are efficient, stable, and economical. This review provides a systematic guide for constructing interface structures of platinum compounds, aiming to promote the sustainable development of hydrogen energy technologies, facilitate their widespread application in the global energy transition, and contribute to achieving carbon neutrality goals and addressing increasingly severe environmental challenges.

Bimetallic Pt-Ni0.5 nanoparticles with enhanced oxidase like activity for Hg2+ detection in water

BACKGROUND

Hg2+ has highly sulfur affinity which was harmful to human health. Noble metal nanomaterials with peroxide-like activity have been widely exploited to develop ultra-sensitive Hg2+ colorimetric detection methods. Unfortunately, using large quantities of H2O2 in these approaches lowered the catalytic activity's high stability, which made the detection signal less reproducible. Thus, it is critical to explore novel oxidases with high catalytic activity to create ultrasensitive, low-cost Hg2+ colorimetric detection method.

RESULTS

In this study, bimetallic Pt-Ni0.5 nanoparticles with oxidase-like activity were synthesized by hydrothermal method, which significantly improved the material's catalytic activity via both geometric and electrical modulation, resulting in sensitive detection of Hg2+ in water. For tap water, drinking water and lake water samples, the limits of detection of the colorimetric method were 0.287 nM, 0.287 nM, 0.51 nM, respectively. A parallel analysis in 3 real samples was confirmed by ICP-MS, the results showed good correlations (R2 > 0.98), indicating the practical reliability of this method.

SIGNIFICANCE

The bimetallic Pt-Ni0.5 nanoparticles with high oxidase-like activity which don't require H2O2 during the catalytic detection process, simplifying the determination procedure, yielding a more stable and dependable output signal for detection and lowering the cost of Hg2+ detection. The sensitivity of the colorimetric sensor in UV-vis mode was 2.8-30 times higher than that of the similar methods. Thus, the developed Hg2+ colorimetric sensor provides stable and economical technical support for ultrasensitive detection of Hg2+ in real water samples. This study will greatly promote the application of rapid trace detection of Hg2+ in water.

Coordinated d-p hybridized hcp@fcc NiRu alloy doped by interstitial atoms for boosting urea-assisted simulated seawater electrolysis at industrial current densities

The production of hydrogen through seawater electrolysis has recently garnered increasing concern. However, hydrogen evolution reaction (HER) by alkaline seawater electrocatalysis is severely impeded by the slow H2O adsorption and H* binding kinetics at industrial current densities. Herein, a face-centered cubic/hexagonal close packed (fcc/hcp) NiRu alloy heterojunction was fabricated on Ni foam (N doped NiRu-inf/NF) by a low-temperature nitrogen plasma activation. Simultaneously, nitrogen atoms are introduced into the alloy to facilitate d-p hybridization. When N doped NiRu-inf/NF is integrated into a dual-electrode cell for urea-assisted seawater electrolysis, it achieves 100 mA cm-2 with an ultra-low voltage of 1.36 V and excellent stability. Density functional theory (DFT) verifies that the robust d-p hybridization among Ni, Ru and N exhibits more energy level matching for H2O molecule adsorption at the Ru sites, while simultaneously reducing the interaction between H* and Ni sites in N-doped NiRu-inf.

Enhanced Alkaline Hydrogen Evolution Reaction via Electronic Structure Regulation: Activating PtRh with Rare Earth Tm Alloying

Developing high-performance electrocatalysts for alkaline hydrogen evolution reaction (HER) is crucial for producing green hydrogen, yet it remains challenging due to the sluggish kinetics in alkaline environments. Pt is located near the peak of HER volcano plot, owing to its exceptional performance in hydrogen adsorption and desorption, and Rh plays an important role in H2O dissociation. Lanthanides (Ln) are commonly used to modulate the electronic structure of materials and further influence the adsorption/desorption of reactants, intermediates, and products, and noble metal-Ln alloys are recognized as effective platforms where Ln elements regulate the catalytic properties of noble metals. Here Pt1.5Rh1.5Tm alloy is synthesized using the sodium vapor reduction method. This alloy demonstrates superior catalytic activity, being 4.4 and 6.6 times more effective than Pt/C and Rh/C, respectively. Density Functional Theory (DFT) calculations reveal that the upshift of d-band center and the charge transfer induced by alloying promote adsorption and dissociation of H2O, making Pt1.5Rh1.5Tm alloy more favorable for the alkaline HER reaction, both kinetically and thermodynamically.

Light-driven assembly of Pt clusters on Mo-NiOx nanosheets to achieve Pt/Mo-NiOx hybrid with dense heterointerfaces and optimized charge redistribution for alkaline hydrogen evolution

Designing cost-effective alkaline hydrogen evolution reaction (HER) catalysts with high water dissociation ability, enhanced hydroxyl transfer rate and optimized hydrogen adsorption free energy (ΔGH*) by a time and energy efficient strategy is pivotal, but still challenging for alkaline water electrolysis. Herein, Pt/Mo-NiOx hybrid consisting of Pt clusters assembled on Mo-doped NiOx nanosheet arrays is prepared on the surface of raw NiMo foam (NMF) by a light-driven strategy to address this challenge. Benefitting from the electronic interaction between Mo-NiOx and Pt, the Pt/Mo-NiOx composite owns optimized ΔGH* and is beneficial for accelerating water dissociation and hydroxyl transfer. As a result, the optimized Pt/Mo-NiOx/NMF electrode displays an exceptional alkaline HER activity with a low overpotential of 62 mV to obtain 100 mA cm-2 and a high Pt mass activity (13.2 times as high as that of commercial 20 wt% Pt/C). Furthermore, the assembled two-electrode cell of Pt/Mo-NiOx/NMF||NiFe-LDH/NF requires a voltage of only 1.549 V to deliver 100 mA cm-2, along with negligible activity decay after 70 h stability test. The present study provides a promising strategy for exploiting high-performance electrocatalysts towards alkaline HER.

Ultrafine Pt-based catalyst decorated with oxygenophilic Ni-sites accelerating alkaline H2O dissociation for efficient hydrogen evolution

Although Pt is a widely adopted commercial catalyst for the hydrogen evolution reaction (HER), its practical application is greatly limited by its prohibitive cost and high energy barrier for H2O dissociation in alkaline media. Herein, an ultrafine Pt-based catalyst decorated with oxygenophilic Ni-sites is rationally designed and successfully synthesized with Pt5(GS)10 (HGS = l-reduced glutathione) nanocluster precursor. The optimized Ni-decorated Pt catalyst (Ni-Pt-C-500) with ultrafine nanoparticles (about 1.6 nm) exhibits a low overpotential (14.0 mV) at 10 mA cm-2 and a mild Tafel slope of 20.8 mV dec-1 in the HER, which is superior to its undecorated counterpart (Pt-C-500), the commercial 20 wt% Pt/C catalyst and most of the previously reported Pt-based electrocatalysts. Experimental observations and theoretical calculations indicate that H2O could be spontaneously adsorbed to Ni-sites of the Ni-Pt-C-500 catalyst. Mechanistic studies reveal that Ni-sites promote HER by accelerating the kinetic of H2O cleavage and optimizing the electronic structure of Pt. This work paves a new avenue for designing other ultrafine hybrid electrocatalysts based on metal nanoclusters to enhance catalytic reaction kinetics.

Optimizing Pt-Based Alloy Electrocatalysts for Improved Hydrogen Evolution Performance in Alkaline Electrolytes: A Comprehensive Review

The splitting of water through electrocatalysis offers a sustainable method for the production of hydrogen. In alkaline electrolytes, the lack of protons forces water dissociation to occur before the hydrogen evolution reaction (HER). While pure Pt is the gold standard electrocatalyst in acidic electrolytes, since the 5d orbital in Pt is nearly fully occupied, when it overlaps with the molecular orbital of water, it generates a Pauli repulsion. As a result, the formation of a Pt-H* bond in an alkaline environment is difficult, which slows the HER and negates the benefits of using a pure Pt catalyst. To overcome this limitation, Pt can be alloyed with transition metals, such as Fe, Co, and Ni. This approach has the potential not only to enhance the performance but also to increase the Pt dispersion and decrease its usage, thus overall improving the catalyst's cost-effectiveness. The excellent water adsorption and dissociation ability of transition metals contributes to the generation of a proton-rich local environment near the Pt-based alloy that promotes HER. Significant progress has been achieved in comprehending the alkaline HER mechanism through the manipulation of the structure and composition of electrocatalysts based on the Pt alloy. The objective of this review is to analyze and condense the latest developments in the production of Pt-based alloy electrocatalysts for alkaline HER. It focuses on the modified performance of Pt-based alloys and clarifies the design principles and catalytic mechanism of the catalysts from both an experimental and theoretical perspective. This review also highlights some of the difficulties encountered during the HER and the opportunities for increasing the HER performance. Finally, guidance for the development of more efficient Pt-based alloy electrocatalysts is provided.