Researchers at Institute of Science Tokyo have uncovered how copper sulfide (CuS) catalysts change their surface during electrochemical CO2 reduction. Using a potential-step method, they found that sulfur and oxygen play distinct roles, steering the reaction toward formic acid or multi-carbon products. This challenges the assumption that catalyst surfaces stay static during operation. The study, published in Materials Advances, shows that applying negative potential partially reduces CuS to metallic copper, while positive potential forms copper oxide. This cycle continuously reshapes the catalyst, improving selectivity. The team suggests future catalyst design should focus on controlled surface transformations rather than just composition. These findings could lead to more efficient CO2 conversion technologies, turning greenhouse gas into useful chemicals using renewable electricity. That supports carbon recycling and sustainable manufacturing, though practical deployment still requires scaling and cost analysis.
