Redox Replacement of Silver on MOF‐Derived Cu/C Nanoparticles on Gas Diffusion Electrodes for Electrocatalytic CO<sub>2</sub> Reduction
Nivedita Sikdar, João R. C. Junqueira, Denis Öhl, Stefan Dieckhöfer, Thomas Quast, Michael Braun, Harshitha Barike Aiyappa, Sabine Seisel, Corina Andronescu, Wolfgang Schuhmann
Abstract
Abstract Bimetallic tandem catalysts have emerged as a promising strategy to locally increase the CO flux during electrochemical CO 2 reduction, so as to maximize the rate of conversion to C−C‐coupled products. Considering this, a novel Cu/C−Ag nanostructured catalyst has been prepared by a redox replacement process, in which the ratio of the two metals can be tuned by the replacement time. An optimum Cu/Ag composition with similarly sized particles showed the highest CO 2 conversion to C 2+ products compared to non‐Ag‐modified gas‐diffusion electrodes. Gas chromatography and in‐situ Raman measurements in a CO 2 gas diffusion cell suggest the formation of top‐bound linear adsorbed *CO followed by consumption of CO in the successive cascade steps, as evidenced by the increasing ν C−H bands. These findings suggest that two mechanisms operate simultaneously towards the production of HCO 2 H and C−C‐coupled products on the Cu/Ag bimetallic surface.