CO poisoning of silver gas diffusion electrodes in electrochemical CO2 reduction

Abstract

Carbon monoxide is the main product in electrochemical CO2 reduction on silver. CO poisoning presents a common challenge in catalytic systems which requires respective research on silver catalysts in the context of electrochemical CO2 reduction. The presence of CO inhibits the catalytic performance by blocking active sites, suggesting the overall process to be limited by CO desorption. Thus, the catalyst poisons itself, leading to decreased CO2 reduction and hydrogen evolution rates. Experimental investigations confirm this effect at varying CO concentrations and current densities. Consequently, CO poisoning has to be assessed when modeling electrochemical CO2 reduction using silver gas diffusion electrodes.