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

The electrochemical CO 2 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 (FE HCOOH ) 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 CO 2 to HCOOH conversion. The synthesized BiIn alloy nanoparticles, derived from the bimetallic metal-organic frameworks, exhibit an impressive CO 2 -to-HCOOH conversion performance due to the Bi-In dual-metal sites effects. • Metal-organic framework derived BiIn alloy was an efficient catalyst for electrochemical CO 2 reduction to HCOOH. • A FE of 92.5% at the current density of 300 mA cm −2 was achieved with a 5170 µmol h −1 cm −2 production rate for HCOOH. • Long-term stability for HCOOH production was achieved with the FE > 80% at the current density of 120 mA cm −2 for 25 h. • Bi-In dual-metal sites provide the optimal binding energy to *OCHO intermediate, thus enhancing the HCOOH production.