title: A site-holding effect of TiO2surface hydroxyl in the photocatalytic direct synthesis of 1,1-diethoxyethane from ethanol.
abstract: To understand the mechanism of the photocatalytic direct synthesis of 1,1-diethoxyethane (DEE) from ethanol is vital for enhancing the reaction efficiency. Based on photocatalytic data of different phase TiO2and F-TiO2catalysts, radical trapping data, and GC-MS data, we proposed a photocatalytic mechanism for the preparation of both DEE in neat ethanol and 2,3-butanediol (2,3-BD) in ethanol-H2O using photocatalytic methods. In neat ethanol, hydroxyl isn't involved in the catalytic cyclic process but hydroxyl has an indirect site-holding effect, thus leading to more hydroxyl groups with higher activity. In ethanol-H2O, although the strong oxidant ˙OH radical is involved, fewer OH groups lead to higher selectivity of 2,3-BD. The interaction of the reactant/solvent with the surface group of the catalyst is important in the activity and selectivity of photocatalytic reactions. This finding gives fundamental insight into the role of TiO2surface hydroxyl in the photocatalytic dehydrogenation process of alcohols and opens a promising path to obtaining both high selectivity and high conversion in TiO2-based photocatalytic activity.
authors.affiliation: Institute of Application Chemistry, Shanxi University, Taiyuan 030006, China. hxzhang@sxu.edu.cn and State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China. zpzhu@sxicc.ac.cn.
authors.forename: Hongxia
authors.identifier: http://orcid.org/0000-0003-0924-4899
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Institute of Application Chemistry, Shanxi University, Taiyuan 030006, China. hxzhang@sxu.edu.cn and State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China. zpzhu@sxicc.ac.cn.
authors.forename: Wenqin
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Institute of Application Chemistry, Shanxi University, Taiyuan 030006, China. hxzhang@sxu.edu.cn and State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China. zpzhu@sxicc.ac.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China. zpzhu@sxicc.ac.cn.
authors.forename: Pengju
authors.initials: P
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China. zpzhu@sxicc.ac.cn.
authors.forename: Zhenping
authors.initials: Z
authors.lastname: Zhu