Yan, Liu; Liang, Xiao-Du; Sun, Yue; Xiao, Liang-Ping; Lu, Bang-An; Li, Guang; Li, Yu-Yang; Hong, Yu-Hao; Wan, Li-Yang; Chen, Chi; Yang, Jian; Zhou, Zhi-You; Tian, Na; Sun, Shi-Gang

CHEMICAL COMMUNICATIONS

2022, 58, 1359-7345

Yan, Liu; Liang, Xiao-Du; Sun, Yue; Xiao, Liang-Ping; Lu, Bang-An; Li, Guang; Li, Yu-Yang; Hong, Yu-Hao; Wan, Li-Yang; Chen, Chi; Yang, Jian; Zhou, Zhi-You; Tian, Na; Sun, Shi-Gang

We synthesized Cu single atoms embedded in a N-doped porous carbon catalyst with a high Faradaic efficiency of 93.5% at -0.50 V (vs. RHE) for CO2 reduction to CO. The evolution of Cu single-atom sites to nanoclusters of about 1 nm was observed after CO2 reduction at a potential lower than -0.30 V (vs. RHE). The DFT calculation indicates that Cu nanoclusters improve the CO2 activation and the adsorption of intermediate *COOH, thus exhibiting higher catalytic activity than CuNx sites. The structural instability observed in this study helps in understanding the actual active sites of Cu single atom catalysts for CO2 reduction.