ja304049x_si_001.pdf (1.6 MB)
Stepwise Photocatalytic Dissociation of Methanol and Water on TiO2(110)
journal contribution
posted on 2012-08-15, 00:00 authored by Qing Guo, Chenbiao Xu, Zefeng Ren, Wenshao Yang, Zhibo Ma, Dongxu Dai, Hongjun Fan, Timothy K. Minton, Xueming YangWe have investigated the photocatalysis of partially
deuterated
methanol (CD3OH) and H2O on TiO2(110)
at 400 nm using a newly developed photocatalysis apparatus in combination
with theoretical calculations. Photocatalyzed products, CD2O on Ti5c sites, and H and D atoms on bridge-bonded oxygen
(BBO) sites from CD3OH have been clearly detected, while
no evidence of H2O photocatalysis was found. The experimental
results show that dissociation of CD3OH on TiO2(110) occurs in a stepwise manner in which the O–H dissociation
proceeds first and is then followed by C–D dissociation. Theoretical
calculations indicate that the high reverse barrier to C–D
recombination and the facile desorption of CD2O make photocatalytic
methanol dissociation on TiO2(110) proceed efficiently.
Theoretical results also reveal that the reverse reactions, i.e, O–H
recombination after H2O photocatalytic dissociation on
TiO2(110), may occur easily, thus inhibiting efficient
photocatalytic water splitting.