Tailoring the interactions of heterogeneous Ag2S/Ag interface for efficient CO2 electroreduction

Electrochemical CO2 reduction reaction (CO2RR) offers an appealing route to simultaneously store intermittent renewable energy as value-added chemicals and close carbon cycle. Silver (Ag) catalyst is a promising candidate for the electrochemical conversion of CO2 to CO, but the electrocatalytic properties are still insufficient for practical applications. Herein, we put forward a strategy to in situ reconstruct a heterogeneous Ag2S/Ag interface structure, in which their strong interactions facilitate CO2RR performance. The in situ reconstructive Ag2S/Ag catalyst achieves a large current density of 421.7 +/- 14.4 mA cm-2 at -0.70 V vs. reversible hydrogen electrode (RHE) and maintains steadily at a current density of 244.5 +/- 31.8 mA cm-2 and CO Faradaic efficiency of 99.1 +/- 0.8 % at -0.49 V vs. RHE for 50 h, superior to state-of-the-art CO-selective Ag-based catalysts. Density functional theory calculations reveal that the in situ reconstructive Ag2S/Ag interface active sites stabilize the *COOH intermediate during CO2RR process.

Automated summary

A strategy to in situ reconstruct a heterogeneous Ag2S/Ag interface structure is proposed for electrochemical CO2 reduction reaction, showing superior performance in terms of high current density and stable CO Faradaic efficiency. Density functional theory calculations reveal that the in situ reconstructive Ag2S/Ag interface active sites stabilize the *COOH intermediate during CO2RR process.