title: Electrochemical Reduction of Carbon Dioxide to Methanol by Direct Injection of Electrons into Immobilized Enzymes on a Modified Electrode.
abstract: We present results for direct bio-electrocatalytic reduction of CO2 to C1 products using electrodes with immobilized enzymes. Enzymatic reduction reactions are well known from biological systems where CO2 is selectively reduced to formate, formaldehyde, or methanol at room temperature and ambient pressure. In the past, the use of such enzymatic reductions for CO2 was limited due to the necessity of a sacrificial co-enzyme, such as nicotinamide adenine dinucleotide (NADH), to supply electrons and the hydrogen equivalent. The method reported here in this paper operates without the co-enzyme NADH by directly injecting electrons from electrodes into immobilized enzymes. We demonstrate the immobilization of formate, formaldehyde, and alcohol dehydrogenases on one-and-the-same electrode for direct CO2 reduction. Carbon felt is used as working electrode material. An alginate-silicate hybrid gel matrix is used for the immobilization of the enzymes on the electrode. Generation of methanol is observed for the six-electron reduction with Faradaic efficiencies of around 10%. This method of immobilization of enzymes on electrodes offers the opportunity for electrochemical application of enzymatic electrodes to many reactions in which a substitution of the expensive sacrificial co-enzyme NADH is desired.
authors.affiliation: Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria. stefanie.schlager@jku.at.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Schlager
authors.affiliation: Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria.
authors.forename: Liviu Mihai
authors.initials: LM
authors.lastname: Dumitru
authors.affiliation: ACIB GmbH, Stahlstraße 14, 4020, Linz, Austria.
authors.forename: Marianne
authors.initials: M
authors.lastname: Haberbauer
authors.affiliation: PROFACTOR GmbH, Im Stadtgut Zone A2, 4407, Steyr, Austria.
authors.forename: Anita
authors.initials: A
authors.lastname: Fuchsbauer
authors.affiliation: Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria.
authors.forename: Helmut
authors.initials: H
authors.lastname: Neugebauer
authors.affiliation: Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Hiemetsberger
authors.affiliation: Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria.
authors.forename: Annika
authors.initials: A
authors.lastname: Wagner
authors.affiliation: Institute of Physical Chemistry, Leopold-Franzens-Universität Innsbruck, Innrain 52c, 6020, Innsbruck, Austria.
authors.forename: Engelbert
authors.initials: E
authors.lastname: Portenkirchner
authors.affiliation: Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Altenbergerstraße 69, 4040, Linz, Austria.
authors.forename: Niyazi Serdar
authors.initials: NS
authors.lastname: Sariciftci
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry*; D004566:Electrodes; D004583:Electrons; D004800:Enzymes, Immobilized / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; D002245:Carbon Dioxide; D000432:Methanol
keywords: CO2 reduction; bio-electrocatalysis; dehydrogenase; enzymes; immobilization