Catalytic methanation over single crystal nickel and ruthenium: Reaction kinetics on different crystal planes and the correlation of surface carbide concentration with reaction rate

The kinetics of the reaction of H 2 and CO over single crystals of nickel ((100) and (111)) and ruthenium ((110) and (001)) have been studied as a function of pressure and H 2 CO ratio. A striking correlation has been observed between the measured surface carbide concentration and the rate of methane production while varying the H 2 CO ratio and the total pressure. This correlation is shown to be a necessary consequence of the reaction mechanism previously proposed [1] for the catalytic methanation reaction over nickel.