Metal-organic framework derived dual-metal sites for electroreduction of carbon dioxide to HCOOH

Abstract

The electrochemical CO2 reduction to formic acid (HCOOH) by Bi-based catalysts has been considered an effective way to solve the energy and environmental crisis. However, achieving high selectivity, high current density, and long-term stability for HCOOH production, remains a substantial challenge. Herein, BiIn alloy nanoparticles (NPs), deriving from the bimetallic metal-organic frameworks, exhibit an excellent HCOOH Faradaic efficiency (FEHCOOH) of 92.5% at the current density of 300 mA cm−2, as well as a production rate of 5170 µmol h−1 cm−2. Moreover, the BiIn alloy NPs also achieve superior stability that over 25 h with less than 10% FE drop at the current density of 120 mA cm−2 in a membrane electrode assembly system. In-situ spectra and theoretical calculations suggest that the Bi-In dual-metal sites can provide the optimal binding energy to *OCHO intermediate, thus accelerating the CO2 to HCOOH conversion.