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

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.

Automated summary

A facile and robust interface reaction method was developed for the controllable synthesis of hierarchically structured flower-like MnO2 hollow microspheres at a low cost. The as-prepared flower-like MnO2 hollow microspheres exhibited excellent low-temperature catalytic activity for toluene oxidation due to their high specific surface area, abundant oxygen vacancies, high content of Mn4+, numerous acidic sites, and strong acidity. This work provides a new strategy for the facile construction of high-performance volatile organic compounds oxidation catalysts with industrial application prospects.