Bioelectrocatalytic CO2 reduction to formate by Candida boidinii formate dehydrogenase overcoming NADH dependence with tailored amino-viologen redox polymers

Abstract

CO₂ reduction to formate through enzymatic systems represents a sustainable pathway for carbon utilization but is often limited by the cost and irreversibility of cofactors like NADH. In this study, we introduce a novel biocathode integrating NAD-dependent formate dehydrogenase (cbFDH) and an amino-viologen redox polymer (NH₂Et-PVI) to act as a mediating artificial cofactor, enabling continuous formate production without re-supply of exogenous cofactors. This bioelectrode achieves a faradaic efficiency of 95.4 % and a 43-fold increase in formate yield over traditional NADH-dependent biocatalytic systems, which highlights the cbFDH/NH₂Et-PVI bioelectrode as a promising advancement for economically viable CO₂ conversion.