Efficient catalytic degradation of toluene at a readily prepared Mn-Cu catalyst: Catalytic performance and reaction pathway

Jian-Rong Li; Wan-Peng Zhang; Chang Li; Chi He

doi:10.1016/j.jcis.2021.01.096

Efficient catalytic degradation of toluene at a readily prepared Mn-Cu catalyst: Catalytic performance and reaction pathway

J Colloid Interface Sci. 2021 Jun:591:396-408. doi: 10.1016/j.jcis.2021.01.096. Epub 2021 Feb 6.

Authors

Jian-Rong Li¹, Wan-Peng Zhang², Chang Li³, Chi He⁴

Affiliations

¹ Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China; Zhejiang Key Laboratory of Urban Environmental Process and Pollution Control, Ningbo Urban Environment Observation and Research Station, Chinese Academy of Sciences, Ningbo 315800, PR China. Electronic address: jrli@iue.ac.cn.
² Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China; Zhejiang Key Laboratory of Urban Environmental Process and Pollution Control, Ningbo Urban Environment Observation and Research Station, Chinese Academy of Sciences, Ningbo 315800, PR China.
³ Center for Excellence in Regional Atmospheric Environment, and Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China.
⁴ State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, PR China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing 101408, PR China. Electronic address: chi_he@xjtu.edu.cn.

PMID: 33631527
DOI: 10.1016/j.jcis.2021.01.096

Abstract

Fabricating of economical transitional metal oxide-based materials with satisfied low-temperature catalytic performance and application perspective is still a challenge in deep degradation of VOCs. Here, Mn-Cu bimetallic oxides were facilely prepared by one-step hydrothermal-redox method, which displayed much higher catalytic activity in toluene oxidation than those synthesized by hydrolysis-driven redox-precipitation or co-precipitation approach. It is shown that the lattice defect and oxygen vacancy concentration over prepared materials can be tuned by controlling Cu/Mn molar ratio. Amongst, spinel structured MnCu_0.5 exhibited the highest catalytic activity, superior durability and water resistance in toluene total oxidation owing to abundant surface adsorbed oxygen species, excellent low-temperature reducibility, and high amounts of Cu⁺ and Mn³⁺. In detail, the reaction rate of MnCu_0.5 was over 9.0 times higher than that of MnCu_0.75, MnCu_0.75-P and MnCu_0.75-H₂O₂ at relative low temperature of 210 °C. The cyclic redox process with easier oxygen species mobility played a key role in the catalytic oxidation of toluene. Typical reaction intermediates as benzyl alcohol, benzaldehyde, benzene, phenol, and benzoquinone could be detected by PTR-MS, which further decomposed to acetone, ethanol, ketone, acetic acid, methanol, formaldehyde and acetaldehyde species by ring opening before total mineralization.

Keywords: Hydrothermal-redox; Mn-Cu bimetallic oxides; PTR-MS; Spinel; Toluene oxidation.