Implications of Surface Strain for Enhanced Carbon Dioxide Reduction on Copper-Silver Alloys

Abstract

The electrochemical reduction of atmospheric carbon dioxide to value added chemicals and fuels using renewable energy is a promising route to a sustainable economy. In this work we present results from the electrochemical reduction of carbon dioxide on copper/silver alloy electrodes alongside pure copper and pure silver in acetonitrile-water electrolyte mixtures. EIS measurements show that the copper/silver alloys exhibit lower charge-transfer resistance when compared to the pure metal electrodes. Reduced product analysis identifies carbon monoxide (CO) as the major product on pure Ag, Ag with alloyed with 10% Cu, and Cu alloyed with 10% Ag with Faradaic efficiencies over 60%. Formate is the major reduced product close to the 50:50 (Cu:Ag) ratio with Faradaic efficiencies exceeding 30%. Our results suggest that changes in the metallic lattice and structural strain of the bimetallic electrodes influences reduced product selectivity.

Energy conversion efficiency comparison of different aqueous and semi-aqueous CO2 electroreduction systems

“…Electroreduction is a widely used method for reducing CO 2 emissions. Research in this eld has been actively progressing recently, with studies reporting the obtainment of valuable products from CO 2 using electrodes such as Cu, Ag, and Au in aqueous solutions, where the faradaic efficiency reached >60%; [3][4][5][6][7] however, many occasions of overvoltages (1-2 V) have been reported as well. Under such circumstances, evaluating the CO 2 reduction using faradaic efficiency is not worthwhile, when compared to other energy conversion methods, e.g., water electrolysis for hydrogen energy production.…”

Electrochemical Reduction of Carbon Dioxide: Recent Advances on Au-Based Nanocatalysts

“…As a result, it is imperative to develop remarkable electrocatalysts which significantly speed up the reaction rate and regulate the reaction selectivity toward the target products [16,17]. To date, different types of metal-based electrocatalysts such as Au [18][19][20][21][22][23], Cu [24][25][26][27][28][29][30][31][32][33][34][35][36], Pd [37][38][39][40][41][42][43][44][45][46], Ag [47][48][49][50][51][52][53][54], Bi [32,[55][56][57][58], Sn [59][60][61][62][63] and Co [64]...…”

Investigation of Electrochemical CO2 Reduction on Cost Effective Copper Zinc Oxide Electrocatalyst

“…Some of the reports have shown that alloying Cu metal with other metals is an efficient way to accomplish particular products at relatively low overpotential. 13,14 On the other hand, the non-noble Zn metal would be a good candidate for CO 2 reduction due to its abundance, cost-effectiveness, and environmentally benign. 15 Hence, the CO 2 reduction activity of Cu is enhanced by the formation of CuZn alloy since Zn is turned out to be slower for the Hydrogen Evolution Reaction (HER) process.…”