Metal-Organic Framework-Derived CuS Nanocages for Selective CO2 Electroreduction to Formate

Electroreduction of CO2 to target products with high activity and selectivity has techno-economic importance for renewable energy storage and CO2 utilization. Herein, we report a hierarchical CuS hollow polyhedron (CuS-HP) for electrocatalytic CO2 reduction (E-CO2R) in neutral pH aqueous media. Under E-CO2R conditions, CuS-HP undergoes structural reconstruction into sulfur-doped metallic Cu catalyst, which promotes formate production with Faradaic efficiency >90% in a wide potential range. The durability of the in situ evolved catalyst has been demonstrated by stable operation for 36 h at a formate partial current density of similar to 16 mA cm(-2) at -0.6 V versus reversible hydrogen electrode. Theoretical thermodynamic analysis reveals that the sulfur-doped Cu(111) facet is responsible for high formate selectivity by promoting formate production and suppressing hydrogen evolution.

Automated summary

An hierarchical CuS hollow polyhedron was reported for electrocatalytic CO2 reduction in neutral pH aqueous media, showing high formate production efficiency. Experimental and theoretical analysis indicated that sulfur-doped Cu(111) facet played a key role in promoting formate selectivity.