A phosphate-derived bismuth catalyst with abundant grain boundaries for efficient reduction of CO2 to HCOOH

Abstract

Electroreduction of CO₂ to HCOOH with high current densities and efficiencies remains a challenge. Herein, we developed a metallic Bi catalyst with abundant grain boundaries through the electrochemical transformation of BiPO₄ nanorods to boost the catalytic performance of the electroreduction of CO₂ to HCOOH. The phosphate-derived Bi catalyst (PD-Bi) achieved an FE of 91.9% for HCOOH at a high current density of −600.0 mA cm⁻². Mechanistic study revealed that the abundant grain boundaries within PD-Bi promoted the adsorption of CO₂ and stabilization of the CO₂˙⁻ intermediate, resulting in facilitated CO₂ activation and thus enhanced catalytic performance.