Amorphous Sn(HPO4)2-derived phosphorus-modified Sn/SnOx core/shell catalyst for efficient CO2 electroreduction to formate

Abstract

Simultaneously achieving high activity, selectivity and stability for electrochemical CO2 reduction reaction (CO2RR) remains great challenges. Herein, a phosphorus-modified Sn/SnOx core/shell (P-Sn/SnOx) catalyst, derived from in situ electrochemical reduction of an amorphous Sn(HPO4)2 pre-catalyst, exhibits high CO2RR performance. The total Faradaic efficiency (FE) of C1 products is close to 100% in a broad potential range from −0.49 to −1.02 V vs. reversible hydrogen electrode, and a total current density of 315.0 mA cm−2 is achieved. Moreover, the P-Sn/SnOx catalyst maintains a formate FE of ∼90% for 120 h. Density functional theory calculations suggest that the phosphorus-modified Sn/SnOx core/shell structure effectively facilitates formate production by enhancing CO2 adsorption and improving free energy profile of formate formation.