Identifying Photocatalytic Active Sites of C 2 H 6 C-H Bond Activation on TiO 2 via Combining First-Principles Ground-State and Excited-State Electronic Structure Calculations.

The activation of C-H bonds at low temperatures has attracted widespread interest in heterogeneous catalysis, which involves complex thermocatalytic and photocatalytic reaction processes. Herein, we systematically investigate the photothermal catalytic process of C-H bond activation in CH dehydrogenation on rutile TiO(110). We demonstrate that the photochemical activity of the CH molecule adsorbed on TiO(110) is site-sensitive and that CH is more easily adsorbed at the Ti site with a lower dehydrogenation energy barrier. The first C-H bond activation of the CH adsorbed at the Ti site tends to occur in the ground state, whereas O-adsorbed CH is more photoactive during the initial adsorption. During the dehydrogenation of CH, the photogenerated electrons are always located at the Ti sites of the TiO substrate while the photogenerated holes can be captured by CH to activate the C-H bond.