Enzymatic conversion of CO2 to formate: The potential of tungsten-containing formate dehydrogenase in flow reactor system

Abstract

This study introduces a novel approach for CO2 reduction to formate using the recombinant formate dehydrogenase 1 (MeFDH1) from Methylorubrum extorquens AM1 as biocatalyst, addressing challenges in activity, productivity, and long-term stability of enzyme. We demonstrate that immobilized MeFDH1 supported by electrochemical reaction system enhances formate production and stability, achieving over 1.7 M concentration with an initial rate of 20 mM/h and near-unity Faradaic efficiency for over 200 hours. In further, the reusability of immobilized MeFDH1 was obtained without significant declination of productivity and selectivity. The electrochemical study of MeFDH1 found the product inhibition in continuous CO2 conversion. To overcome this challenge and build efficient process, the integration of a flow reactor system and in-situ separation unit further improved the system's performance and scalability. This advancement in enzymatic CO2 conversion suggests the potential of biocatalysis towards addressing global warming through sustainable chemical synthesis.