Reactions of H2, CH4, C2H6, and C3H8 with [(MgO)n]+ Clusters Studied by Density Functional Theory

The reactions of CH4 with [(MgO)n]+ cluster cations (n=1–5, or 7) and those of C2H6 and C3H8 with [(MgO)2]+ are studied by density functional theory (B3LYP functional/TZVP basis set). Comparison with CCSD(T) calculations shows that these results are affected by errors between −6.5 and +5.1 kJ mol−1. The barriers of −26.1 and −27.0 kJ mol−1 predicted for CH4/(MgO)+ and C3H8/[(MgO)2]+, respectively, are in agreement with the observed hydrogen abstraction reaction. The reactions of H2 with [(MgO)n]+ cluster cations are studied for comparison, and the energy of hydrogenation is considered as reactivity descriptor for the metal oxide clusters in this type of reaction.