Acetone Formation from Photolysis of 2-Propanol on Anatase-TiO_2(101)

Abstract

Photocatalysis of 2-propanol on A-TiO2(101) has been investigated using a temperature programed desorption method with 266 nm laser light. A clear mechanism is proposed for photodissociation of 2-propanol on A-TiO2(101). Acetone product on five coordinate Ti4+ sites is formed in a stepwise manner in which the O-H dissociation proceeds first and then followed by secondary C-H dissociation of 2-propanol while H atoms are transferred to the adjacent bridge bond oxygen (BBO) sites. Low temperature water is formed in a thermally driven process via H-atom on BBO in exchange with isopropyl groups of molecule 2-propanol, while isopropyl radical desorbs at high temperature during the TPD process. The observation demonstrates the prospect of TiO2 as a photocatalyst for degradation of organics