Superior performance in catalytic combustion of toluene over mesoporous ZSM-5 zeolite supported platinum catalyst

Catalytic combustion over zeolite supported platinum catalysts is regarded as one of the efficient methods for removal of volatile organic compounds (VOCs). In this work, we show a preparation of Pt loaded mesoporous ZSM-5 zeolite (Pt/Meso-ZSM-5) with various cations. The sample N-2 sorption isotherms and TEM image show abundant mesoporosity existing in the zeolite crystals. The catalytic toluene combustion tests show that the Pt/Meso-ZSM-5 catalysts have higher activities than conventional ZSM-5 supported Pt-0 catalysts (Pt/ZSM-5), which is related to their difference in the concentration of active sites Pt and the rate of mass transfer. Particularly, after reduction with hydrogen at 300 degrees C, the Pt nanoparticles supported on Meso-ZSM-5 with K+ and Cs+\ cations (Pt-R/Meso-KZSM-5 and Pt-R/Meso-CsZSM-5) exhibit much higher activities than those on Meso-ZSM-5 with Na+ and H+ cations, which is well consistent with their order of the Pt-0 concentration. For example, Pt-R/Meso-KZSM-5 gives the temperature for conversion of 98% toluene (T-98) at only 175 degrees C, while Pt-R/Meso-HZSM-5 shows the T-98 at 190 degrees C. More importantly, Pt-R/Meso-KZSM-5 has a long life, and its activity cannot be influenced by the water and CO2. These features are critically important for practical applications of these catalysts in the future. (C) 2015 Elsevier B.V. All rights reserved.