The temperature dependence of electrochemical CO2 reduction on Ag and CuAg alloys
Rafaël E. Vos, Jeroen P. Smaak, Marc T. M. Koper
Abstract
Ag is often studied as catalyst for electrochemical CO2 reduction as it shows high selectivity towards CO and is easily alloyed with Cu to enhance performance using CuAg catalysts. In this study, we investigated the effect of temperature on Ag and CuAg catalysts and compare these with previous results on Au and Cu catalysts. We show that the temperature effect is complicated as it shows an interplay with CO2 concentration, potential and mass transport. It is therefore crucial to deconvolute these parameters and study the effect of temperature under different conditions. Moreover, we show that alloying Ag with Cu can inhibit some of the deactivation effects observed at high temperatures on pure Cu. CuAg alloys can prevent the dominance of hydrogen evolution at elevated temperatures, although an optimum of C2+ products with temperature is still observed.