Isolated Cu-Sn diatomic sites for enhanced electroreduction of CO2 to CO
Wei Liu, Haoqiang Li, Pengfei Ou, Jing Mao, Lili Han, Jun Song, Jun Luo, Huolin L. Xin
Abstract
Electrochemical CO2 reduction reaction (CO2RR) to high-value product, CO, not only provides a key feedstock for the well-established Fischer—Tropsch process but also mitigates the greenhouse effect. However, it suffers from sluggish reaction kinetics, competitive hydrogen evolution reaction, and low selectivity. Herein, we report non-precious Cu-Sn diatomic sites anchored on nitrogen-doped porous carbon (CuSn/NPC) as an efficient catalyst for CO2RR to CO. The catalyst exhibits outstanding selectivity with CO Faradaic efficiency (FE) up to 99.1%, much higher than those of individual Cu (66.2%) and Sn (51.3%) single-atom catalysts. Moreover, high stability is confirmed by consecutive 24 h electrolysis with high selectivity from CO2 to CO. Theoretical calculations reveal an obvious activation of CO2 with weakened C—O bonds and distorted CO2 configuration upon chemisorption on the CuSn/NPC catalyst. It is also suggested CuSn/NPC is more selective for the CO2RR with dominant CO production during the electrolysis, rather than the competing hydrogen evolution reaction.