Facile fabrication of flower-like MnO2 hollow microspheres as high-performance catalysts for toluene oxidation

Wenxiu Gu; Chenqi Li; Jianhao Qiu; Jianfeng Yao

doi:10.1016/j.jhazmat.2020.124458

Facile fabrication of flower-like MnO₂ hollow microspheres as high-performance catalysts for toluene oxidation

J Hazard Mater. 2021 Apr 15:408:124458. doi: 10.1016/j.jhazmat.2020.124458. Epub 2020 Nov 4.

Authors

Wenxiu Gu¹, Chenqi Li², Jianhao Qiu³, Jianfeng Yao⁴

Affiliations

¹ School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China. Electronic address: guwenxiu@jiangnan.edu.cn.
² School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China.
³ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China.
⁴ Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Chemical Engineering, Nanjing Forestry University, Nanjing, Jiangsu, 210037, China. Electronic address: jfyao@njfu.edu.cn.

PMID: 33168316
DOI: 10.1016/j.jhazmat.2020.124458

Abstract

A facile and robust interface reaction method for controllable synthesis of hierarchically structured flower-like MnO₂ hollow microspheres was developed at a low cost. With MnCO₃ microspheres as homologous templates, KMnO₄ was used to conduct redox reactions with the surface layer of the MnCO₃ microspheres to form porous flower-like MnO₂. Then, the internal template was removed by HCl etching to obtain flower-like MnO₂ hollow microspheres. HCl plays the dual role of removing the template and generating oxygen vacancies through acid etching. The as-prepared flower-like MnO₂ hollow microspheres exhibited excellent low-temperature catalytic activity for toluene oxidation owing to the desirable features of a high specific surface area, abundant oxygen vacancies, high content of Mn⁴⁺, a high number of acidic sites and a strong acidity. This work provides a new strategy for the facile construction of high-performance volatile organic compounds oxidation catalysts with industrial application prospects.

Keywords: Acid etching; Flower-like MnO(2) hollow microsphere; Interface reaction; Oxygen vacancies; Toluene catalytic oxidation.