Water-Gas Shift Reaction Catalyzed by Redox Enzymes on Conducting Graphite Platelets

Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
Journal of the American Chemical Society (Impact Factor: 11.44). 10/2009; 131(40):14154-5. DOI: 10.1021/ja905797w
Source: PubMed

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.

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