Kinetics of the Methanation of Carbon Dioxide over Ruthenium on Titania

The catalytic methanation of carbon dioxide is currently used exculusively in combination with the methanation of carbon monoxide: The synthesis gas for the production of ammonia is purified by simultaneous methanation of carbon dioxide and carbon monoxide, which are catalyst poisons in the ammonia synthesis, down to a concentration of less than 5 vol.-ppm. Another potential application of the catalytic carbon dioxide methanation could emerge in long-duration manned space missions: The reaction could close the oxygen cycle consisting of separating carbon dioxide from the stale cabin air, converting carbon dioxide with hydrogen to methane and water, decomposing the water via electrolysis into hydrogen and oxygen and resupplying the oxygen into the cabin air.