Selective Electrochemical Oxidation of Methane to Ethanol over the Co3O4/La2O2CO3 Heterojunction Catalyst

Catalyzing methane (CH4) at room temperature to value-added products is a promising approach, but high product selectivity remains a challenge. In this study, La2CoO3 was used as a precursor to synthesize xLC (xCo3O4/La2CoO3) by adjusting the molar ratio of Co and La. When glycerol was added for hydrothermal modification, a carbon source was introduced into xLC to form an efficient heterojunction material xLC-C (xCo3O4/La2O2CO3) capable of converting CH4 to ethanol at 2.2 V (vs RHE). Moreover, 3.5LC-C was found to convert CH4 with a current density difference of up to 17.86 mA/cm2 and ethanol yields of 627 μmol/gcat/h. Density functional theory calculations indicate that the high reactivity results from an increased internal charge distribution following the introduction of La2O2CO3 into the Co3O4 system, which provides electron transport and reactive oxygen species to activate the C-H bond. Co3O4 serves as the active phase, providing a site for the adsorption and conversion of CH4. The presence of La2O2CO3 in this study reduces the reaction residence time, thus inhibiting C-C coupling reactions between intermediates such as CH4 and HCHO, impeding the formation of long-chain alcohols and achieving high product selectivity.

Enhanced CO2 Hydrogenation to Methanol Using out-of-Plane Grown MoS2 Flakes on Amorphous Carbon Scaffold

The conversion of excess carbon dioxide (CO2) into valuable chemicals is critical for achieving a sustainable society. Among various catalysts, molybdenum disulfide (MoS2) has demonstrated potential for CO2 hydrogenation to methanol. However, its catalytic activity has yet to be fully optimized, and scalable, industrially viable production methods remain underdeveloped. In this work, a chemical vapor deposition (CVD) approach is introduced to grow vertically oriented MoS2 crystals on an amorphous carbon template. This method enhances the exposure of vacancy-rich basal planes, which are crucial for stable catalytic performance. The 2H-MoS2 flakes, supported on a conductive carbon scaffold, exhibit catalytic activity, achieving a net space-time yield of 2.68 gMeOH gcat⁻¹ h⁻¹ with a selectivity of 82.5% under mild conditions (264 °C, 10 bar). This work highlights a significant step toward the industrial application of MoS2-based catalysts for CO2 conversion, bridging the gap between fundamental research and scalable implementation.

Synthesis of defect-rich La2O2CO3 supports for enhanced CO2-to-methanol conversion efficiency

Converting CO2 to methanol is crucial for addressing fuel scarcity and mitigating the greenhouse effect. Cu-based catalysts, with their diverse surface states, offer the potential to control reaction pathways and generate reactive H* species. However, a major challenge lies in oxidizing active Cu0 species by water generated during the catalytic process. While nonreducible metal oxides are beneficial in stabilizing metallic states, their limited capability to generate surface oxygen vacancies (OV) hinders CO2 activation. Herein, we present a strategy by doping Nd into a La2O2CO3 (LOC) support, enhancing OV formation by disrupting its lattice dyadicity. This leads to higher Cu0 concentration and improved CO2 activation. The resulting Cu/LOC:Nd catalyst notably outperforms Cu/LOC and CuZnAl catalysts, achieving a methanol yield of 9.9 moles of methanol per hour per mole of Cu. Our approach opens up possibilities for enhancing Cu-based catalysts in CO2 conversion.

Efficient Role of Nanosheet-Like Pr2O3 Induced Surface-Interface Synergistic Structures over Cu-Based Catalysts for Enhanced Methanol Production from CO2 Hydrogenation

In a complex heterogeneous metal-catalyzed reaction process, unique cooperative effects between metal sites and surface-interface active sites, as well as favorable synergy between surface-interface active sites, can play crucial roles in improving their catalytic performances. In this work, a ZnO-modified Cu-based catalyst over defect-rich Pr₂O₃ nanosheets for high-efficiency CO₂ hydrogenation to produce methanol was successfully constructed. It was demonstrated that an as-fabricated nanosheet-like Cu-based catalyst presented several structural advantages including the formation of highly dispersive Cu⁰ sites and the coexistence of abundant defective Pr³⁺-V_o-Pr³⁺ structures (V_o: oxygen vacancy) and interfacial Cu-O-Pr sites. Combining structural characterization and catalytic reaction results with density functional theory calculations, it was clearly unveiled that the synergy between surface defective structures and Cu-Pr₂O₃ interfaces over the catalyst remarkably promoted the adsorption of CO₂ and CO intermediate, thus boosting the CO₂ hydrogenation simultaneously via both the formate intermediate pathway and the intense reverse water-gas shift reaction-derived CO hydrogenation pathway, along with a high space-time yield of methanol of 0.395 g_MeOH·g_cat^-1·h^-1 under mild reaction conditions (260 °C and 3.0 MPa). The study provides a new strategy to construct high-performance Cu-based catalysts for high-efficiency CO₂ hydrogenation to produce methanol and a deep understanding of the promotional roles of synergy between surface-interface active sites in the CO₂ hydrogenation.

Highly water-soluble dimeric and trimeric lanthanide carbonates with ethylenediaminetetraacetates as precursors of catalysts for the oxidative coupling reaction of methane

Highly water-soluble dimeric and trimeric lanthanide carbonates with ethylenediaminetetraacetates have been obtained. Their coordination modes provide a model for the oxidative coupling of methane of lanthanide carbonates.

Selective methylation of toluene using CO2 and H2 to para-xylene

Toluene methylation with methanol to produce xylene has been widely investigated. A simultaneous side reaction of methanol-to-olefin over zeolites is hard to avoid, resulting in an unsatisfactory methylation efficiency. Here, CO₂ and H₂ replace methanol in toluene methylation over a class of ZnZrO _x -ZSM-5 (ZZO-Z5) dual-functional catalysts. Results demonstrate that the reactive methylation species (H₃CO*; * represents a surface species) are generated more easily by CO₂ hydrogenation than by methanol dehydrogenation. Catalytic performance tests on a fixed-bed reactor show that 92.4% xylene selectivity in CO-free products and 70.8% para-xylene selectivity in xylene are obtained on each optimized catalyst. Isotope effects of H₂/D₂ and CO₂/¹³CO₂ indicate that xylene product is substantially generated from toluene methylation rather than disproportionation. A mechanism involving generation of reactive methylation species on ZZO by CO₂ hydrogenation and migration of the methylation species to Z5 pore for the toluene methylation to form xylene is proposed.

Engineering well-defined rare earth oxide-based nanostructures for catalyzing C1 chemical reactions

In this review, we summarize the nanostructural engineering and applications of rare earth oxide-based nanomaterials with well-defined compositions, crystal phases and shapes for efficiently catalyzing C1 chemical reactions.

State of the art and perspectives in heterogeneous catalysis of CO2 hydrogenation to methanol

The ever-increasing amount of anthropogenic carbon dioxide (CO₂) emissions has resulted in great environmental impacts, the heterogeneous catalysis of CO₂ hydrogenation to methanol is of great significance.

Bimetallic NiIr nanoparticles supported on lanthanum oxy-carbonate as highly efficient catalysts for hydrogen evolution from hydrazine borane and hydrazine

La₂O₂CO₃-supported NiIr nanoparticles (NPs) have been facilely synthesized via a sodium–hydroxide-assisted reduction approach and used as highly efficient catalysts for hydrogen generation from hydrazine borane and hydrous hydrazine.