Localized Ti-III mediated dissociative electron transfer for carbon halogen bond activation on TiO2

	Localized Ti-III mediated dissociative electron transfer for carbon halogen bond activation on TiO2
	Zhu, Qian 1,2; Wang, Yuanyuan 1,2; Zhang, Hongna 1,2; Duan, Ran 1,2; Chen, Chuncheng 1,2; Song, Wenjing 1,2; Zhao, Jincai 1,2
刊名	APPLIED CATALYSIS B-ENVIRONMENTAL
	2017-12-15
卷号	219 页码:322-328
关键词	Photocatalytic Dehalogenation Carbon-halogen Bond Activation Monochloroacetic Acid Dissociative Electron Transfer Titanium Dioxide
英文摘要	The reductive activation of the carbon halogen (C-X) bond is a key step in the transformation of organic halides via bond dissociation. Monochloroacetic acid (MCA), a typical recalcitrant aliphatic halide, was previously shown to be reduced by hydrated electrons (e(aq)), requiring 254 nm irradiation. Here, we demonstrate the efficient hydrogenation of MCA to acetic acid (HOAc) with high selectivity using TiO2 electrons accumulated under the bandgap (3.2 eV) excitation in the presence of methanol as a hole scavenger. The reaction occurs via a single electron transfer in concert with C-Cl cleavage (concerted dissociative electron transfer, DET) to give (CH2COOH)-C-center dot, which is then subjected to the subsequent 1e(-)/1H(+) process to give HOAc. The in situ visible and infrared spectroscopic characterizations reveal the critical role of localized Ti-III states in C-CI activation, whereas conduction band or shallow trapped electrons are not active in this process. The photocatalytic reduction rate slowed down with an increase in the intervening carbon atoms (monohalogenated propionic and butyric acids) between TiO2 surface and the C-X bond, which is attributed to the decrease in the electron transfer driving force. (C) 2017 Elsevier B.V. All rights reserved.
语种	英语
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/41266]
专题	化学研究所_光化学实验室
作者单位	1.Chinese Acad Sci, CAS Res Educ Ctr Excellence Mol Sci, Key Lab Photochem, Inst Chem, Beijing 100190, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
推荐引用方式 GB/T 7714	Zhu, Qian,Wang, Yuanyuan,Zhang, Hongna,et al. Localized Ti-III mediated dissociative electron transfer for carbon halogen bond activation on TiO2[J]. APPLIED CATALYSIS B-ENVIRONMENTAL,2017,219:322-328.
APA	Zhu, Qian.,Wang, Yuanyuan.,Zhang, Hongna.,Duan, Ran.,Chen, Chuncheng.,...&Zhao, Jincai.(2017).Localized Ti-III mediated dissociative electron transfer for carbon halogen bond activation on TiO2.APPLIED CATALYSIS B-ENVIRONMENTAL,219,322-328.
MLA	Zhu, Qian,et al."Localized Ti-III mediated dissociative electron transfer for carbon halogen bond activation on TiO2".APPLIED CATALYSIS B-ENVIRONMENTAL 219(2017):322-328.