Nano-MnOx prepared by redox method for toluene oxidation removal from air

Abstract

Catalytic oxidation is an efficient VOCs removal technology with great potential and development advantages. The key to the oxidative elimination of VOCs lies in the development and application of the catalyst with high efficiency. In this work, the nano-MnO_x catalysts were prepared by redox method and the catalytic oxidation performance of toluene was studied. The calcination temperature could effectively change the surface chemical composition and the nano-MnO_x catalyst structures, which could effectively regulate the number of active centers on the catalyst surface to improve the adsorption, activation, and oxidation ability of the nano-MnO_x catalysts for toluene molecules. The nano-MnO_x catalyst dominated by the MnO₂ phase, which was prepared at the calcination temperature of 400 °C, had a high specific surface area, developed porosity, abundant reactive oxygen species, and oxygen vacancies. The structural characteristics are conducive to the adsorption, activation, and oxidation of toluene molecules, and thus exhibited excellent toluene catalytic oxidation activity. At the reaction temperature of 140 °C, the toluene oxidation conversion was as high as 99.4 %, and the toluene conversion remained above 96.6 % after experiencing a 690 min stability test.