A DFT study on the mechanism of photoselective catalytic reduction of 4-bromobenzaldehyde in different solvents employing an OH-defected TiO2 cluster model

作者：Gan, Hanlin; Peng, Liang^*; Gu, Feng Long^*

来源：Physical Chemistry Chemical Physics, 2017, 19(40): 27755-27764.

DOI：10.1039/c7cp04366j

• EFFECTIVE CORE POTENTIALS
• MOLECULAR CALCULATIONS
• WATER
• ADSORPTION
• (TIO2)(N)
• ELECTRON
• ENERGY
• SOLAR
• PHOTOREDUCTION
• NANOPARTICLES

Density functional theory calculations are employed to study the mechanism of photoselective catalytic reduction of 4-bromobenzaldehyde (4-BBA) in acetonitrile and in ethanol solvents. A totally relaxed Ti3O9H6 cluster model is proposed to represent titanium dioxide (TiO2) surfaces. The reduction selectivity of an adsorbed 4-BBA molecule on Ti3O9H6 has been investigated. Owing to the difference in the proton and H atom donating capabilities between explicit CH3CN and C2H5OH solvent molecules, the photocatalytlc reduction of 4-BBA is the debromination process in acetonitrile, where as in ethanol it is the carbonyl reduction process. Therefore 4-BBA can be selectively reduced to benzaldehyde in acetonitrile and 4-bromobenzyl alcohol in ethanol, respectively. Our computational results have verified the reaction mechanism proposed by experiments and show that the debromination of 4-BBA would be efficient if both 4-BBA and Ti3O9H6 have an extra photoelectron. The Ti3O9H6 cluster, playing a role as a hydrogen source and a bridge to transfer photoelectrons from bulk TiO2, would have potential to be an Ideal molecular model for understanding photocatalytlc reactions on the TiO2 surface.

• 出版日期2017-10-28