Structure and crystal phase transition effect of Sn doping on anatase TiO2 for dichloromethane decomposition

Yang Yang; Hao Li; Haitao Zhao; Ruiyang Qu; Shuo Zhang; Wenshuo Hu; Xinning Yu; Xinbo Zhu; Shaojun Liu; Chenghang Zheng; Xiang Gao

doi:10.1016/j.jhazmat.2019.02.103

Structure and crystal phase transition effect of Sn doping on anatase TiO₂ for dichloromethane decomposition

J Hazard Mater. 2019 Jun 5:371:156-164. doi: 10.1016/j.jhazmat.2019.02.103. Epub 2019 Feb 27.

Authors

Yang Yang¹, Hao Li¹, Haitao Zhao¹, Ruiyang Qu¹, Shuo Zhang¹, Wenshuo Hu¹, Xinning Yu¹, Xinbo Zhu¹, Shaojun Liu², Chenghang Zheng¹, Xiang Gao³

Affiliations

¹ State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China.
² State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China; School of Energy and Power, Jiangsu University of Science and Technology, Zhenjiang, 212003, China. Electronic address: phoenix205@zju.edu.cn.
³ State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027, China. Electronic address: xgao1@zju.edu.cn.

PMID: 30849570
DOI: 10.1016/j.jhazmat.2019.02.103

Abstract

Efficient removal of chlorinated volatile organic compounds (CVOCs) has received great attention because of the considerable harm that they cause to the environment and to human health. Developing novel catalysts and exploring the catalytic activation and deconstruction mechanism of CVOCs molecule are always the focus in this field. Here, a set of Sn doped TiO₂ catalysts were investigated for the decomposition of dichloromethane (DCM). Rietveld refinement of the XRD patterns showed that Sn ions can uniformly disperse into TiO₂ and induce the crystal transition of anatase. Meanwhile, such decorating can induce an increase in specific surface area and affect the surface oxygen vacancy concentration of these samples, which have been demonstrated by N₂ adsorption and XPS, respectively. Catalytic performance tests indicated that the Sn_0.2Ti_0.8O₂ has the best activity for DCM decomposition, and a lower CH₃Cl selectivity than that of pure TiO₂. Computational results suggested the dominant surface (110) of rutile Sn_0.2Ti_0.8O₂ is more beneficial for the adsorption/dissociation of DCM molecule than that of anatase TiO₂ (101). That's because the anchoring of DCM to Sn sites and electron enrichment on the surface bridge oxygen atoms of rutile Sn_0.2Ti_0.8O₂ (110) can promote the nucleophilic substitution process for breaking of CCl bonds.

Keywords: Adsorption energy; Anatase TiO(2); Dichloromethane; Dissociation energy; Rutile.