Effect of calcium addition in plasma catalysis for toluene removal by Ni/ZSM-5 : Acidity/basicity, catalytic activity and reaction mechanism

Weicheng Xu; Bingxu Chen; Xueding Jiang; Feng Xu; Xin Chen; Limin Chen; Junliang Wu; Mingli Fu; Daiqi Ye

doi:10.1016/j.jhazmat.2019.122004

Effect of calcium addition in plasma catalysis for toluene removal by Ni/ZSM-5 : Acidity/basicity, catalytic activity and reaction mechanism

J Hazard Mater. 2020 Apr 5:387:122004. doi: 10.1016/j.jhazmat.2019.122004. Epub 2019 Dec 31.

Authors

Weicheng Xu¹, Bingxu Chen², Xueding Jiang³, Feng Xu³, Xin Chen³, Limin Chen⁴, Junliang Wu⁴, Mingli Fu⁴, Daiqi Ye⁵

Affiliations

¹ School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, China. Electronic address: xwc1030@163.com.
² School of Environment and Energy, South China University of Technology, Guangzhou 510006, China.
³ School of Environmental and Chemical Engineering, Foshan University, Foshan 528000, China.
⁴ School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangzhou 510006, China.
⁵ School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; National Engineering Laboratory for VOCs Pollution Control Technology and Equipment, Guangzhou 510006, China. Electronic address: cedqye@scut.edu.cn.

PMID: 31901844
DOI: 10.1016/j.jhazmat.2019.122004

Abstract

The effect of Ca modification on the Ni/ZSM-5 catalyst for efficient toluene oxidation was studied in a plasma-catalytic system. The Ni/ZSM-5 and Ca-Ni/ZSM-5 catalysts were prepared by a wet impregnation method and characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Pyridine-FTIR spectroscopy and temperature programmed desorption of ammonia (NH₃-TPD). Among the catalysts tested, the Ca-Ni/ZSM-5 sample showed the best potential for toluene conversion (90.2%) and CO₂ selectivity (70.7%). Pyridine-FTIR spectra and NH₃-TPD results proved that the introduction of Ca and Ni onto ZSM-5 caused a decrease in the strong and weak acidic sites. In addition, gas chromatography/mass spectrometry (GC-MS) result showed that the Ca-Ni/ZSM-5 catalyst reduced the production of undesirable byproducts (such as p-nitrotoluene and methyl benzoate). Calcium in the Ni/ZSM-5 system influenced the acidity and other surface characteristic of the catalyst, as well as directly impacting the reactive plasma species and the intermediates. Finally, possible reaction mechanisms in the plasma catalysis of toluene were also proposed.

Keywords: Acidity; Calcium oxide; Mechanism; Non-thermal plasma; Reaction; Toluene.

Publication types

Research Support, Non-U.S. Gov't