Redox Replacement of Silver on MOF-Derived Cu/C Nanoparticles on Gas Diffusion Electrodes for Electrocatalytic CO2 Reduction

Sikdar, N. and Junqueira, J.R.C. and Öhl, D. and Dieckhöfer, S. and Quast, T. and Braun, M. and Aiyappa, H.B. and Seisel, S. and Andronescu, C. and Schuhmann, W.

Volume: 28 Pages:
DOI: 10.1002/chem.202104249
Published: 2022

Bimetallic tandem catalysts have emerged as a promising strategy to locally increase the CO flux during electrochemical CO2 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 CO2 conversion to C2+ products compared to non-Ag-modified gas-diffusion electrodes. Gas chromatography and in-situ Raman measurements in a CO2 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 increasingνC−H bands. These findings suggest that two mechanisms operate simultaneously towards the production of HCO2H and C−C-coupled products on the Cu/Ag bimetallic surface. © 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.

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