Dual-active sites design of Snx-Sby-O-GO nanosheets for enhancing electrochemical CO2 reduction via Sb-accelerating water activation

Electrochemical CO2 reduction reaction (eCO2RR) is a promising approach for the sustainable development of energy and environment, yet the control over selectivity of eCO2RR is challenging and entails intelligent active site design. Herein, we firstly propose dual-active sites design of Snx-Sby-O-GO nanosheets (NSs) for controlling the reaction pathways. The Snx-Sby-O-GO NSs catalyst possesses large-size ultrathin structure and controllable Sn/Sb ratio, strengthening the interaction at the active site with OCHO* intermediate. The optimized Sn7-Sb3-O-GO NSs exhibit a HCOOH selectivity of 96.5% and partial current density of − 21.6 mA cm−2. The experiments and theory calculations show that the introduction of Sb secondary active site can accelerate water activation for forming unique *H species and the binding strength of OCHO* key intermediates, thereby enhancing the HCOOH selectivity in eCO2RR. This work lends credence to the novel metal-metal dual-active sites design strategy for eCO2RR sustainable energy conversion. An ultrathin Sn7-Sb3-O-GO electrocatalyst with dual active sites exhibits a high HCOOH selectivity of 96.5% and partial current density of − 21.6 mA cm−2 for eCO2RR. [Display omitted] •A metal-metal dual active sites strategy for eCO2RR sustainable energy conversion is proposed.•Snx-Sby-O-GO catalysts possess large-size 2D structure and controllable Sn/Sb ratio.•The introduction of Sb site can facilitate HCOOH production via accelerating H2O activation.•Sn7-Sb3-O-GO exhibits a HCOOH selectivity of 96.5% and partial current density of − 21.6 mA cm−2.