Adjusting *CO adsorption configuration over tandem trimetallic AuAgCu heterojunction boosts CO2 electroreduction to ethanol via asymmetric C-C coupling
摘要
Rationally modulating the adsorption configuration of the key *CO intermediate could facilitate carbon-carbon (C-C) coupling to generate multi-carbon products in the electrochemical CO2 reduction reaction. In this work, theoretical calculations reveal that C-C coupling via atop-adsorbed *CHO and hollow-adsorbed *CO over Cu sites is an energetically favorable pathway. As a proof of concept, a tandem trimetallic AuAgCu heterojunction (Au@Ag/Cu) was prepared, where the atop-adsorbed *CO over Au@Ag sites could migrate to Cu sites with hollow adsorption configuration, and then the asymmetric C-C coupling via transferred hollow-adsorbed *CO and existed atop-adsorbed *CHO over Cu sites facilitates the formation of the ethanol product, exhibiting a maximum Faraday efficiency of 65.9% at a low potential of −0.3 V vs. reverse hydrogen electrode. Our work provides new insights into the intrinsic understanding of tandem catalysis by regulating adsorption configuration of the intermediate products.