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 C 2 H 6 dehydrogenation on rutile TiO 2 (110). We demonstrate that the photochemical activity of the C 2 H 6 molecule adsorbed on TiO 2 (110) is site-sensitive and that C 2 H 6 is more easily adsorbed at the Ti 5c site with a lower dehydrogenation energy barrier. The first C-H bond activation of the C 2 H 6 adsorbed at the Ti 5c site tends to occur in the ground state, whereas O br -adsorbed C 2 H 6 is more photoactive during the initial adsorption. During the dehydrogenation of C 2 H 6 , the photogenerated electrons are always located at the Ti 4+ sites of the TiO 2 substrate while the photogenerated holes can be captured by C 2 H 6 to activate the C-H bond.