MnO_2 nanoparticles encapsuled in spheres of Ce-Mn solid solution: Efficient catalyst and good water tolerance for low-temperature toluene oxidation

摘要

The high-efficient catalyst is critical for volatile organic compounds (VOCs) catalytic oxidation. MnO2 nanoparticles encapsuled in spheres of Ce-Mn solid solution (package structure) are controllable designed and applied for the catalytic oxidation of toluene, a representative of VOCs. Our study indicates that the obtained Ce1M2 (molar ratio of Ce:Mn = 1:2) catalyst displays much better toluene oxidation activity than pristine MnO2 and CeO2. Meanwhile, the shell of Ce-Mn solid solution contributes to superior thermal stability and resistance against 5 vol% H2O. The synergistic effect between two oxides is maximized by the package structure, giving rise to high BET surface area, good reducibility and fast oxygen mobility, which in turn leads to the outstanding catalytic performance in Ce1Mn2. Additionally, in situ DRIFTS results indicate that intermediate species -COO and -O-CH(=O) are found during the catalytic oxidation of toluene over Ce1Mn2, which is mainly dominated by MvK mechanism.