Ag-decorated Cu2O porous hollow catalyst for promoting CO2 electroreduction to C2H4 via enrichment of CO

Electrocatalytic CO2 reduction reaction (CO2RR) to multi-carbon product, especially for ethylene (C2H4), provides a favorable pathway for carbon neutrality and renewable energy storage. However, the second-order C-C coupling reactions in CO2RR need always the high activation/driven energy in dynamics originating from the trace C1 intermediate product. Herein, we synthesized the Ag-decorated Cu2O porous hollow core-shell catalyst named Ag@Cu2O where Ag nanoparticles uniformly distributed on inner the surface of the hollow Cu2O (HCu2O) via the sacrificial template method. Benefiting from the synergistic hollow structure and electron transfer from Cu and Ag to O, Ag@Cu2O catalyst delivers the excellent C2H4 Faradaic Efficiency (FE) of 55 % +/- 2 % at -1.0 V (vs. RHE), which is superior to the most reported catalysts. More importantly, in situ infrared spectroscopy and density functional theory (DFT) calculations reveal the introduction of Ag can decrease the activation energy required for *CO and C-C coupling.