By using a pulse microreactor in conjunction with an emissionless infrared diffuse reflectance spectrometer, the dynamics of adsorbed CO as well as produced CH4 were measured and effects of alkaline carbonate were investigated for the surface reaction of methanation on Ru Al2O3 catalyst. Alkaline carbonate added to the Ru catalyst decreased the rate constant for CO bond dissociation, but scarcely affected the hydrogenation of the surface carbon species produced. Alkaline carbonate shifted the infrared absorption band of adsorbed CO to a lower frequency as a result of the increase in electron density in the Ru metal. It is concluded that the effect of alkaline carbonate is an electronic one whereby the CO bond dissociation in the methanation is influenced. The suppressing effect of alkaline carbonate is discussed in terms of a proposed mechanism for the CO bond dissociation which takes into account the electronic effect.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry