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Electrochemical CO 2 reduction (ECR) to value-added products such as formate/formic acid is a promising approach for CO 2 mitigation. Practical ECR requires long-term stability at industrially relevant reduction rates, which is challenging due to the rapid degradation of most catalysts at high current densities. Herein, we report the development of a bismuth (Bi) gas diffusion electrode on a polytetrafluoroethylene-based electrically conductive silver (Ag) substrate (Ag@Bi), which exhibits high Faradaic efficiency (FE) for formate of over 90 % in 1 M KOH and 1 M KHCO 3 electrolytes. The catalyst also shows high selectivity of formic acid above 85 % in 1 M NaCl catholyte, which has a bulk pH of 2-3 during ECR, at current densities up to 300 mA cm -2 . In 1 M KHCO 3 condition, Ag@Bi maintains formate FE above 90 % for at least 500 hours at the current density of 100 mA cm -2 . We found that the Ag@Bi catalyst degrades over time due to the leaching of Bi in the NaCl catholyte. To overcome this challenge, we deposited a layer of Ag nanoparticles on the surface of Ag@Bi to form a multi-layer Ag@Bi/Ag catalyst. This designed catalyst exhibits 300 hours of stability with FE for formic acid ≥70 % at 100 mA cm -2 . Our work establishes a new strategy for achieving the operational longevity of ECR under wide pH conditions, which is critical for practical applications., (© 2024 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

Atomically precise hydrido gold nanoclusters are extremely rare but interesting due to their potential applications in catalysis. By optimization of molecular precursors, we have prepared an unprecedented N-heterocyclic carbene-stabilized hydrido gold nanocluster, [Au 24 (NHC) 14 Cl 2 H 3 ] 3+ . This cluster comprises a dimer of two Au 12 kernels, each adopting an icosahedral shape with one missing vertex. The two kernels are joined through triangular faces, which are capped with a total of three hydrides. The hydrides are detected by electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy, with density functional theory calculations supporting their position bridging the six uncoordinated gold sites. The reactivity of this Au 24 H 3 cluster in the electrocatalytic reduction of CO 2 is demonstrated and benchmarked against related catalysts.

We present enhanced electrocatalytic activity of three-dimensional graphene scaffolds by decoration with one-dimensional Co x Ni 1-x MOF nanostructures (0 ≤x≤ 1). The decreased overpotential and fast kinetics of the oxygen evolution reaction as compared with the existing materials are shown. The developed bimetallic MOF/3DG composites have great potential to be used in electrocatalytic water oxidation.