Pd/silicalite-1: An highly active catalyst for the oxidative removal of toluene.

Journal: Journal of environmental sciences (China)
PMID:

Abstract

Catalytic combustion is thought as an efficient and economic pathway to remove volatile organic compounds, and its critical issue is the development of high-performance catalytic materials. In this work, we used the in situ synthesis method to prepare the silicalite-1 (S-1)-supported Pd nanoparticles (NPs). It is found that the as-prepared catalysts displayed a hexagonal prism morphology and a surface area of 390-440 m/g. The sample (0.28Pd/S-1-H) derived after reduction at 500°C in 10 vol% H showed the best catalytic activity for toluene combustion (T = 180°C and T = 189°C at a space velocity of 40,000 mL/(g·hr), turnover frequency (TOF) at 160°C = 3.46 × 10 sec, and specific reaction rate at 160°C = 63.8 µmol/(g·sec)), with the apparent activation energy (41 kJ/mol) obtained over the best-performing 0.28Pd/S-1-H sample being much lower than those (51-70 kJ/mol) obtained over the other samples (0.28Pd/S-1-A derived from calcination at 500°C in air, 0.26Pd/S-1-im derived from the impregnation route, and 0.27Pd/ZSM-5-H prepared after reduction at 500°C in 10 vol% H). Furthermore, the 0.28Pd/S-1-H sample possessed good thermal stability and its partial deactivation due to CO or HO introduction was reversible, but SO addition resulted in an irreversible deactivation. The possible pathways of toluene oxidation over 0.28Pd/S-1-H was toluene → p-methylbenzoquinone → maleic anhydride, benzoic acid, benzaldehyde → carbon dioxide and water. We conclude that the good dispersion of Pd NPs, high adsorption oxygen species concentration, large toluene adsorption capacity, strong acidity, and more Pd species were responsible for the good catalytic performance of 0.28Pd/S-1-H.

Authors

  • Linke Wu
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
  • Jiguang Deng
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
  • Yuxi Liu
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
  • Lin Jing
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
  • Xiaohui Yu
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
  • Xing Zhang
    Department of Hepatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
  • Ruyi Gao
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
  • Wenbo Pei
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
  • Xiuqing Hao
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
  • Ali Rastegarpanah
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
  • Hongxing Dai
    Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, Key Laboratory of Advanced Functional Materials, Education Ministry of China, Laboratory of Catalysis Chemistry and Nanoscience, Department of Environmental Chemical Engineering, School of Environmental and Chemical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China. Electronic address: hxdai@bjut.edu.cn.