Mesoporous Nanosized Manganese Dioxides for Efficient Toluene Oxidation

An efficient approach to synthetize the sandwich-like graphene-supported manganese oxides nanosheets (G-MnO2) had been developed for catalytic combustion of toluene by employing sandwich-like graphene-silica nanosheets (G-silica) as intermediates. The as-prepared G-MnO2 not only inherited the two- dimensional structure of reduced graphene, high specific surface areas, the unique mesoporous structure, good dispersion, but also possessed numerous nanoparticles of crystalline MnO2 with the size of about 5 nm on each nanosheet. Such unique features had enhanced significantly the catalytic performance and catalytic stability of MnO2 for toluene oxidation. As a consequence, with the help of sandwich-like G-silica intermediates, the T-50 and T-90 of G-MnO2 for toluene was 240 degrees C (3.92 mu mol center dot g(-1) h(-1)) and 262 degrees C (7.06 mu mol center dot g(-1) h(-1)), respectively, and even after 30 h at 288 degrees C, the conversion of toluene could still be maintained at 99.7% (GHSV= 60 000mL center dot g(-1) h(-1)).