Chlorine-modulated tin oxide as an efficient catalyst toward carbon dioxide electrochemical reduction

Abstract

Electrochemical conversion of CO2 into value-added chemicals such as formic acid shows promise in carbon neutralization for carbon-intensive manufacturing industry, such as ironsteel industry or ammonia production. However, low product selectivity and competitive hydrogen evolution over Sn-based catalysts severely lowers the energy efficiency of this process and increases the cost of downstream product separation. In this work, we demonstrated a facile strategy to improve conversion efficiency of CO2 at a relatively low overpotential by incorporating chlorine element into tin oxide. We found that the less electronegative chlorine than oxygen could lower the oxidation state of surface Sn to an optimal level for CO2 reduction. As a result, the chlorine-modulated Sn showed an overall CO2 conversion Faradaic efficiency of 82.9% at -0.783 V vs RHE, over 43% higher than those over commercial Sn foil and SnO2-derived nanoparticles