Water gas shift reaction

From Wikipedia, the free encyclopedia

The water gas shift reaction is an inorganic chemical reaction in which water and carbon monoxide react to form carbon dioxide and hydrogen (water splitting):

CO + H₂O → CO₂ + H₂

The water gas shift reaction is part of steam reforming of hydrocarbons^[1] and is involved in the chemistry of catalytic converters. It was discovered by Italian physicist Felice Fontana in 1780. The reaction is slightly exothermic.^[1]

While this reaction could be used to produce hydrogen, the high temperatures required make it cost-prohibitive. The generation of hydrogen has significant promise as a replacement clean-burning fuel, however, this reaction is usually done via the byproducts of fossil fuel combustion. The carbon monoxide can also be generated by bogs or other waste regenerative means by physical/chemical processes such as bog and landfill fires.

Attempts to lower the reaction temperature of this reaction have been done primarily with a catalyst such as Fe₃O₄ (magnetite), or other transition metals and transition metal oxides.

The reverse water gas shift reaction has recently found a possible application in In-Situ Resource Utilization on Mars to provide oxygen for fuel.

The water gas shift reaction is sensitive to temperature, with the tendency to shift towards reactants as temperature increases due to Le Chatelier's principle. In fuel-rich hydrocarbon combustion processes, the water gas reaction at equilibrium state is often employed as a means to provide estimates for molar concentrations of burnt gas constituents.