Highly selective electrocatalytic CO2 reduction to liquid C2 products by means of a tandem catalytic system
Nan Wang, Yuan Zhang, Xiaoxin Tian, Mingming Sun, Lei Yuan, Huiyong Wang, Jianji Wang
Abstract
Electrocatalytic CO 2 reduction for the synthesis of high value-added multi-carbon (C 2+ ) products is a promising strategy to achieve energy storage and carbon neutrality, However, to acquire high selectivity of C 2+ products remains a challenge. Herein, Ag NCs@Ag-MOF with highly dispersed Ag nanoclusters (NCs) and Cu-O 2 N 2 -COF with Cu-O 2 N 2 active sites were designed, synthesized and then coupled for the conversion of CO 2 to liquid C 2 products (ethanol and acetate). Faradaic efficiency (FE) of the liquid C 2 products was 90.9% at -0.98 V (vs. RHE), which is 1.9 times that of Cu-O 2 N 2 -COF in direct CO 2 electroreduction and the highest liquid C 2 products selectivity reported so far. The current density reached 324.8 mA cm -2 at -1.2 V (vs. RHE). In situ infrared spectroscopy and density functional theory calculations showed that the tandem catalytic system significantly enhanced the accumulation of *CO on the catalyst and promoted *CO-*CO coupling, thus significantly improving the selectivity of liquid C 2 products.