Selective hydrogenation of acetylene to ethylene on anatase TiO2 through first-principles studies

Titanium dioxide (TiO2) alone is rarely reported to have exciting performance towards heterogeneous hydrogenation reactions. In this work, we demonstrate via density functional theory (DFT) calculations that anatase TiO2 with oxygen vacancies (Ovs), which provides frustrated Lewis pairs (FLPs) from surface Ti and O atoms for the heterolytic dissociation of hydrogen, can effectively hydrogenate acetylene to ethylene. Meanwhile, the mechanisms of H2 activation and acetylene hydrogenation with several structure–reactivity correlations are well established, suggesting the potential catalytic reactivity in the presence of Ovs on anatase TiO2 surfaces. Then, the reactivity of anatase TiO2 towards acetylene hydrogenation is preliminarily confirmed by experimental studies which show that the existence of Ovs after reduction leads to higher reactivity. These results can provide important implications for the further development of selective hydrogenation catalysts based on earth-abundant materials.