Engineering the interface charge redistribution and boosted kinetics via polyoxometalate for efficient carbon dioxide electroreduction in acidic medium

Abstract

The development of electrocatalytic CO₂ reduction reaction (ECO₂RR) which can achieve carbon neutrality goals in acidic medium can effectively solve the problems of carbonate formation and low CO₂ utilization efficiency, but the inhibition of hydrogen evolution reaction (HER) is challenging. Thus, a co-modification strategy of electrolyte and electrocatalyst has been proposed to solve this issue. In a polyoxometalate (POM) H₆PV₃Mo₉O₄₀ modified acidic medium, the highest Faradaic efficiency (FE) and current density for carbonaceous product of POM-CuSe/rGO reach 90.8% and −176.2 mA·cm⁻², respectively. Detailed research shows that the modification for catalyst by POM results in a redistribution of interfacial charges which favors the stable adsorption of *CO, as well as a reduction in the lateral size from 42 ∼ 1400 to 27 ∼ 167 nm. While the POM modification of the electrolyte leads to enhanced kinetics and suppressed CO₃²⁻ production, achieving a single pass conversion efficiency for CO of up to 69.0%. This work proposes a new strategy of POM co-modification for electrolyte and electrocatalyst to enhance the efficiency of acidic CO₂ conversion for industrial applications.