Abstract
The decrease of greenhouse gases such as CO2 has become a key challenge for the human kind and the study of the electrocatalytic properties of CO2-reducing enzymes such as formate dehydrogenases is of importance for this goal. In this work, we study the covalent bonding of Desulfovibrio vulgaris Hildenborough FdhAB formate dehydrogenase to chemically modified gold and low-density graphite electrodes, using electrostatic interactions for favoring oriented immobilization of the enzyme. Electrochemical measurements show both bioelectrocatalytic oxidation of formate and reduction of CO2 by direct electron transfer (DET). Atomic force microscopy and quartz crystal microbalance characterization, as well as a comparison of direct and mediated electrocatalysis, suggest that a compact layer of formate dehydrogenase was anchored to the electrode surface with some crosslinked aggregates. Furthermore, the operational stability for CO2 electroreduction to formate by DET is shown with approximately 100% Faradaic yield.
Highlights
The increase of CO2 atmospheric concentration plays a major role in climate change and global warming
Aminophenyl (AP) groups on the gold surface are formed by electrochemical reduction of a diazonium salt derivative and subsequently the non-modified gold regions are blocked by self-assembling MH (Figure 1C)
The covalent binding of DvH-formate dehydrogenases (FDH) to Au/4-ATP and low-density graphite (LDG)/ AP electrodes modulated by electrostatic orientations allows measuring efficient direct electron transfer (DET)-based bioelectrocatalysis
Summary
The increase of CO2 atmospheric concentration plays a major role in climate change and global warming. The greenhouse effects caused by current emissions may be irreversible for at least 1000 years after such emissions have stopped.[1] A negative emission balance that reduces the amount of CO2 is one of the most important challenges ever faced by the human kind. CO2 has intrinsic kinetic inertia and high thermodynamic stability making it difficult to either trap or reduce. Formic acid/ formate is a stable product that can be obtained by bielectronic reduction of CO2 (eq 1). It has several advantages because it is liquid at standard temperature and is a good energy vector that can be stored and employed in different energy processes such as in fuel cells or synthesis of chemicals.[2]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
