CO 2-reforming of methane on transition metal surfaces

Abstract

The mechanisms of CO 2-reforming of methane on Cu(111), Ni(111), Pd(111), Pt(111), Rh(111), Ru(001), Ir(111) and Fe(110) have been investigated by the the unity bond index-quadratic exponential potential (UBI-QEP) method. This method was named as the bond order conservation Morse potential (BOC-MP) approach before, but it has been generalized and renamed now. The heats of chemisorption ( Q) for all involved adspecies, activation barriers (Δ E) and enthalpy changes (Δ H) for forward and reverse reactions were evaluated. The calculations indicated that both the dissociation of CH 4 and the dissociation of CO 2 are rate-determining steps and that they are promoted by each other. A small amount of OH radical may account for the lower activity for the CO 2-reforming of methane. The activity sequence of catalysts is Fe>Ni>Rh>Ru>Ir>Pd>Pt>Cu. The most appropriate catalyst for CO 2-reforming is Ru. The most suitable non-noble catalyst is Ni.