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

• Published in: Journal of the American Chemical Society 2009-10, Vol.131 (40), p.14154-14155
• Main Authors: Lazarus, Oliver, Woolerton, Thomas W, Parkin, Alison, Lukey, Michael J, Reisner, Erwin, Seravalli, Javier, Pierce, Elizabeth, Ragsdale, Stephen W, Sargent, Frank, Armstrong, Fraser A
• Format: Article
• Language: English
• Subjects: Aldehyde Oxidoreductases - chemistry; Carbon Dioxide - chemistry; Carbon Monoxide - chemistry; Catalysis; Escherichia coli - enzymology; Gases - chemistry; Graphite - chemistry; Hydrogen - chemistry; Multienzyme Complexes - chemistry; Oxidation-Reduction; Oxidoreductases - chemistry; Thermoanaerobacterium - chemistry; Water - chemistry
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja905797w

The water−gas shift (WGS) reaction (CO + H2O ⇆ CO2 + H2) is of major industrial significance in the production of H2 from hydrocarbon sources. High temperatures are required, typically in excess of 200 °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 °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.