Integrated Electrochemical Biomass Oxidation and CO2 Reduction over Ultra-wide Potential Window

Abstract

Electrochemical reduction of carbon dioxide (CO₂) coupled with biomass oxidation using renewable electricity is considered as a promising strategy for carbon management. However, achieving both high selectivity and large current density over wide potential window remains a significant challenge, hindering practical applications. In this study, a Ni/Fe dual metal-atom catalyst is developed for CO₂ reduction, achieving nearly 100 % CO selectivity across an ultra-wide potential window of 1.6 V, surpassing state-of-the-art catalysts. Remarkably, this high CO selectivity is maintained above 98 % even after 100 hours of continuous operation at an industrial current density of 200 mA cm⁻², demonstrating excellent long-term stability. When integrated into a solar electricity-driven CO₂ reduction coupled 5-hydroxymethylfurfural oxidation system, nearly 100 % CO Faradaic efficiency and 90 % 2,5-furandicarboxylic acid yield are simultaneously obtained. Theoretical calculations reveal that the rate-limiting step for the CO₂ reduction reaction varies with the applied potential, and the synergistic interaction between Ni and Fe atoms effectively lowers the limiting energy barrier. This work offers valuable insights for the strategic design and synthesis of catalysts with high activity and selectivity across wide potential window, providing a versatile platform for coupling CO₂ reduction with diverse anodic biomass oxidation reactions and renewable energy sources.