title: Water-gas shift reaction catalyzed by redox enzymes on conducting graphite platelets.
abstract: The water-gas shift (WGS) reaction (CO + H(2)O <==> CO(2) + H(2)) is of major industrial significance in the production of H(2) from hydrocarbon sources. High temperatures are required, typically in excess of 200 degrees C, using d-metal catalysts on oxide supports. In our study the WGS process is separated into two half-cell electrochemical reactions (H(+) reduction and CO oxidation), catalyzed by enzymes attached to a conducting particle. The H(+) reduction reaction is catalyzed by a hydrogenase, Hyd-2, from Escherichia coli, and CO oxidation is catalyzed by a carbon monoxide dehydrogenase (CODH I) from Carboxydothermus hydrogenoformans. This results in a highly efficient heterogeneous catalyst with a turnover frequency, at 30 degrees C, of at least 2.5 s(-1) per minimum functional unit (a CODH/Hyd-2 pair) which is comparable to conventional high-temperature catalysts.
authors.affiliation: Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
authors.forename: Oliver
authors.initials: O
authors.lastname: Lazarus
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Woolerton
authors.forename: Alison
authors.initials: A
authors.lastname: Parkin
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lukey
authors.forename: Erwin
authors.initials: E
authors.lastname: Reisner
authors.forename: Javier
authors.initials: J
authors.lastname: Seravalli
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Pierce
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Ragsdale
authors.forename: Frank
authors.initials: F
authors.lastname: Sargent
authors.forename: Fraser A
authors.initials: FA
authors.lastname: Armstrong
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry; D002248:Carbon Monoxide / Q000737:chemistry; D002384:Catalysis; D004926:Escherichia coli / Q000201:enzymology; D005740:Gases / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D009097:Multienzyme Complexes / Q000737:chemistry*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry*; D046950:Thermoanaerobacterium / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D005740:Gases; D009097:Multienzyme Complexes; D014867:Water; D002245:Carbon Dioxide; D006108:Graphite; D002248:Carbon Monoxide; D006859:Hydrogen; D010088:Oxidoreductases; C029746:uptake hydrogenase; D000445:Aldehyde Oxidoreductases; C019823:carbon monoxide dehydrogenase