The design of the hierarchical rectifying interfaces of unconventionally metal/carbon by building corrosion-resistant Bi-Sn core protected by ultrathin carbon layers is desired to address the low activity and strong hydrogen evolution reaction of conventional metal/carbon catalysts, where it is indicated that the hierarchical rectifying interfaces can constructe a charge emitter, and thus induce the asymmetric electronic perturbation and faster electron exchange for boosting CO2 activation and *OCHO adsorption toward nucleophilic reaction process of *OCHO-Metal.
Abstract
Developing metal/carbon materials as durable electrocatalysts for electrochemical CO2 reduction is of great importance for maintaining long-term activity of metal sites. However, the uncertainty associated with the interaction of metal–carbon restricts the exposure of active sites and the inhibition of the hydrogen evolution reaction. Herein, we have successfully synthesized a hierarchical bimetal/carbon catalyst with unconventional rectifying interfaces (Bi-Sn@C), which works as a charge emitter for efficiently bending CO2 to enhance the adsorption and hydrogenation of activated *CO2 and the generation of *OCHO intermediate by the nucleophilic reaction process due to the electronic perturbation at rectifying interfaces and electron delocalization of the bimetallic cores. The Bi-Sn@C demonstrates up to HCOOH faradic efficiency of 93.06% with energy efficiency of 70.6% at −0.52 V (vs. RHE) and low overpotential of 320 mV in a flow electrolyzer, and operates continuously for more than 160 h due to the protective mechanisms of the carbon shell. Experimental results and theoretical calculations reveal that the hierarchical rectifying interfaces of Bi-Sn@C show an apparent non-uniform distribution of charge and low energy barrier of *OCHO-to-*HCOOH for facilitating the reaction kinetics of formate production.
InfoMat, EarlyView. Read More
