Activation of ethane in the metathesis reaction on silica-supported tantalum hydride: a quantum-chemical study

Abstract

The structures of the (H4Si2O5)O2TaR and (H4Si2O5)O2TaRH2 clusters (R = H, Me, or Et), which model the main structural units of the catalytic cycle of the ethane metathesis on silica-supported tantalum hydride, were studied using the density functional theory at the B3LYP level. Even at high temperatures, activation of ethane cannot proceed via a two-step mechanism involving the oxidative addition of ethane and reductive elimination of hydrogen to form pentavalent tantalum compounds.