Hydrogenolysis and Hydroisomerization of Neopentane on Titanium and Zirconium Hydrides Stabilized on the Surface of SiO2: A Theoretical Study by Density Functional Theory

The model reactions of neopentane hydrogenolysis and hydroisomerization on transition metal hydrides (≡ Si?O)₃M^IVH (1), (=eqSi?O)₂MIVH² (2), and (≡Si?O)₂M^IIIH (3) (M = Zr, Ti) immobilized on the surface of silica were studied by density functional theory. It was shown that the hydrogenolysis of neopentane could occur on all the three types of metal hydrides, the catalytic activity of reaction centers increasing along the series M(IV) monohydrides 1 < M(IV) dihydrides 2 < M(III) hydrides 3. At the same time, the isomerization of the hydrocarbon skeleton of neopentane observed experimentally on titanium-based systems could only be explained by the participation of Ti(III) hydrides.