Controlled Tip Curvature of CuSiO 3 Promotes C–C Coupling for Efficient CO 2 Electroreduction to C 2 Products

Electroreduction of CO2 to multicarbon products offers a promising strategy to carbon neutrality, yet practical application is hindered by sluggish C-C coupling kinetics and competing hydrogen evolution reaction (HER). To overcome these challenges, we propose a controllable synthesis method for tailoring the CuSiO3 tip curvature, which manipulates the local electric field to regulate the C-C coupling barrier and suppress HER, thereby enhancing product selectivity. In particular, the high tip curvature catalyst (HC-CuSiO3-1) exhibits a strong tip-enhanced electric field and stable hydrophobicity, achieving a Faradaic efficiency of 96.2% for C2 products at -0.55 V. Via a variety of in situ techniques and theoretical calculation, the enhanced C2 selectivity over HC-CuSiO3-1 is attributed to the promotion of CO2 adsorption and activation to form the *CHO intermediate, which facilitates subsequent asymmetric *COCHO coupling. This work provides insight into C-C coupling pathways and guides the rational design of local electric field enhanced electrocatalysts for CO2 reduction.