Dual‐Site Activation for Efficient Acidic CO ₂ Electroreduction at Industrial‐Level Current Densities

Abstract

Abstract Electroreduction of CO 2 to formic acid in acidic media offers a promising approach for value‐added CO 2 utilization. However, achieving high selectivity for formic acid in acidic electrolytes remains challenging due to the competitive hydrogen evolution reaction (HER), particularly at industrially relevant current densities. Herein, a charge redistribution modulation strategy is demonstrated by constructing the CuS /SnS 2 Mott–Schottky catalyst to enhance formic acid selectivity. Experiments and calculation results reveal the broadening of Sn orbitals and reduced orbital symmetry of Sn orbitals contribute to enhanced CO 2 adsorption, while the modulated Cu sites with a stronger Lewis acid character stabilize * OCHO intermediates more effectively. This enables dual‐site activation for efficient CO 2 electroreduction into formic acid synthesis. Consequently, the optimized CuS/SnS 2 catalysts achieve a maximum formic acid Faradaic efficiency (FE) of 99% in acidic electrolytes and maintain selectivity above 80% at a current density of 1 A cm −2 , significantly surpassing the performance of CuS and SnS 2 alone. Moreover, the excellent selectivity across pH‐universal electrolytes demonstrates that dual‐site activation is a promising strategy for designing highly efficient CO 2 reduction reaction catalysts.