Efficient electrocatalytic reduction of CO2 to HCOOH by bimetallic In-Cu nanoparticles with controlled growth facet

The electrochemical reduction of CO2 to formic acid (HCOOH) by Indium (In)-based materials have been considered an effective way to solve the energy crisis. Unfortunately, In-based materials face a low selectivity for HCOOH in CO2 reduction reaction (CO2RR) systems. Here, we have successfully prepared bimetallic InxCuy (x, y are the molar ratio) nanoparticles (NPs) electrocatalysts. For the first time, we adjust the growth direction of the electrocatalysts crystal facets by changing the In/Cu ratio in the electrocatalysts structure, so that the Faraday efficiency of HCOOH by In-based materials are raised to a new level (90 % at -1.2 V vs. RHE). Indeed, DFT calculations further showed that the In (101) facet of in InxCuy NPs stabilizes the *OCHO intermediate more effectively, thereby reducing the potential for CO2 to HCOOH. The insights gained from this work can lay the foundation for designing efficient electrocatalysts for the reduction of CO2 to HCOOH.