Redox-Active Crystalline Coordination Catalyst for Hybrid Electrocatalytic Methanol Oxidation and CO2 Reduction

Abstract

Hybrid CO₂ electroreduction (HCER) is recognized as an important strategy to improve the total value of redox products and energy conversion efficiency. In this work, a coordination catalyst model system (Ni₈ -TET with active oxidation sites, Ni-TPP with active reduction sites and PCN-601 with redox-active sites) for HCER was established for the first time. Especially, PCN-601 can complete both anodic methanol oxidation and cathodic CO₂ reduction with FE_HCOOH and FE_CO over 90 %. The performance can be further improved with light irradiation (FE nearly 100 %). DFT calculations reveal that the transfer of electrons from Ni^II ₈ clusters to metalloporphyrins under electric fields results in the raised oxidizability of Ni₈ clusters and the raised reducibility of metalloporphyrin, which then improves the electrocatalytic performance. This work serves as a well-defined model system and puts forward a new design idea for establishing efficient catalysts for hybrid CO₂ electroreduction.

Keywords: Bifunctional Crystalline Catalysts; Crystalline Coordination Compounds; Hybrid CO2 Electroreduction; Methanol Oxidation.