H2-induced CO adsorption and dissociation over Co/Al2O3 catalyst

The activation of adsorbed CO is an important step in CO hydrogenation. The results from TPSR of pre-adsorbed CO with H-2 and syngas suggested that the presence of H-2 increased the amount of CO adsorption and accelerated CO dissociation. The H-2 was adsorbed first, and activated to form H* over metal sites, then reacted with carbonaceous species. The oxygen species for CO2 formation in the presence of hydrogen was mostly OH*, which reacted with adsorbed CO subsequently via CO*+OH* -> CO2*+H*; however, the direct CO dissociation was not excluded in CO hydrogenation. The dissociation of C-O bond in the presence of H proceeded by a concerted mechanism, which assisted the Boundourd reaction of adsorbed CO on the surface via CO*+2H* -> CH*+OH*. The formation of the surface species (CH) from adsorbed CO proceeded as indicated with the participation Of Surface hydrogen. was favored in the initial step of the Fischer-Tropsch synthesis.