Tin-Modified ɑ-MnO2 catalyst with high performance for benzene Oxidation, ozone decomposition and particulate matter filtration

Catalytic oxidation is promising to eliminate VOCs. The challenge is to realize high efficiency under high space velocities and low oxidation temperatures. In this work, Sn-modified ɑ-MnO2 was prepared via a facile redox protocol with varied Sn additions. The oxidation activity for 460 ppm benzene under 120 L/g/h space velocity reached a maximum level at a moderate Sn incorporation. The performance of this SnMn composite in terms of benzene conversion, CO2 production, water and NO2 resistance and cyclability was even better than those of commercial hopcalite catalyst. Easily accessible acid sites, abundant reactive oxygen vacancies and weakened Mn-O bonds were paramount to the diffusion of benzene molecules and transportation of surface oxygen, which were advantageous for the excellent benzene abatement. Finally, mechanic insights into the surface interaction between benzene and oxygen species were provided through comprehensive experimental investigations. The SnMn composite was also good at ozone decomposition and PM2.5 filtration.