Nonthermal plasma catalysis for toluene decomposition over BaTiO3-based catalysts by Ce doping at A-sites: The role of surface-reactive oxygen species

Kang Wu; Yuhai Sun; Jing Liu; Juxia Xiong; Junliang Wu; Jin Zhang; Mingli Fu; Limin Chen; Haomin Huang; Daiqi Ye

doi:10.1016/j.jhazmat.2020.124156

Nonthermal plasma catalysis for toluene decomposition over BaTiO₃-based catalysts by Ce doping at A-sites: The role of surface-reactive oxygen species

J Hazard Mater. 2021 Mar 5:405:124156. doi: 10.1016/j.jhazmat.2020.124156. Epub 2020 Nov 12.

Authors

Kang Wu¹, Yuhai Sun², Jing Liu³, Juxia Xiong¹, Junliang Wu⁴, Jin Zhang¹, Mingli Fu⁴, Limin Chen⁴, Haomin Huang⁴, Daiqi Ye⁵

Affiliations

¹ School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
² School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; Guangdong Provincial Engineeringand Technology Research Centre for Environmental Risk Prevention and Emergency Disposal (SCUT), Guangzhou 510006, PR China.
³ School of Electric Power, South China University of Technology, Guangzhou 510640, PR China.
⁴ School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, PR China; Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control (SCUT), Guangzhou 510006, PR China; National Engineering Laboratoryfor VOCs Pollution Control Technology and Equipment (SCUT), Guangzhou 510006, PR China.
⁵ School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China; School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, PR China; Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control (SCUT), Guangzhou 510006, PR China; National Engineering Laboratoryfor VOCs Pollution Control Technology and Equipment (SCUT), Guangzhou 510006, PR China. Electronic address: cedqye@scut.edu.cn.

PMID: 33246817
DOI: 10.1016/j.jhazmat.2020.124156

Abstract

The insights on the primary surface-reactive oxygen species and their relation with lattice defects is essential for designing catalysts for plasma-catalytic reactions. Herein, a series of Ba_1-xCe_xTiO₃ perovskite catalysts with high specific surface areas (68.6-85.6 m² g^-1) were prepared by a facile in-situ Ce-doping strategy and investigated to catalytically decompose toluene. Combining the catalysts with a nonthermal plasma produced a significant synergy effect. The highest decomposition efficiency (100%), CO_x selectivity (98.1%), CO₂ selectivity (63.9%), and the lowest O₃ production (0 ppm) were obtained when BC₄T (Ce/Ti molar ratio = 4:100) was packed in a coaxial dielectric barrier discharge reactor at a specific input energy of 508.8 J L^-1. The H₂-TPR, temperature-programmed Raman spectra, EPR and OSC results suggested that superoxides (^•O₂^-) were the primary reactive oxygen species and were reversibly generated on the perovskite surface. Molecular O₂ was adsorbed and activated at the active sites (Ti³⁺-V_O) via an electron transfer process to form ^•O₂^-. Surface-adsorbed ^•O₂^- had a greater effect on the heterogeneous surface plasma reactions than the dielectric constant, and enhanced the toluene decomposition and intermediate oxidation. A possible reaction path of toluene decomposition was also proposed.

Keywords: Perovskite; Plasma catalysis; Reactive oxygen species; Synergy effect; Toluene.