Low-temperature VOCs oxidation performance of Pt/zeolites catalysts with hierarchical pore structure

Synergistic Effect of ZSM-5 Zeolite in Pt–CeO2–TiO2/ZSM-5 Catalysts for Highly Efficient Catalytic Oxidation of VOCs

“…Moreover, in comparison with Pt/ZSM-5 catalyst, a distinct shift of CO adsorption bands toward the higher wavenumber is observed for the Pt–CeTi/ZSM-5 catalysts. This may be connected to the improved electron-transfer ability of CeO 2 –TiO 2 mixed oxides to the Pt nanoparticles by the strong Pt/CeO 2 –TiO 2 interaction. ,,, The CO-pulse chemisorption technique was also employed to further investigate the Pt dispersion of the Pt–CeTi/ZSM-5 catalysts. It can be seen from Table that the Pt dispersion of the Pt–CeTi/ZSM-5 catalysts first increases and then decreases with the enlargement of Ce/Ti molar ratio, and the Pt–CeTi/ZSM-5­(10/1) catalyst possesses the highest Pt dispersion (41%), which is basically consistent with the results of CO in situ DRIFTS.…”

“…Nevertheless, the relatively small and sole micropores of ZSM-5 zeolites strongly hindered the mass transfer process, and the noble metal nanoparticles easily agglomerated on the surface of zeolites at higher temperature due to the weaker metal–support interaction. To solve these problems, some researchers constructed zeolites with hierarchical porous structure by engineering suitable mesopores. − As an example, Guo et al prepared the Pt/mZSM-5-A8 catalyst with the hierarchical structure by adjusting the synthesis condition. They revealed this catalyst was superior to the common Pt/ZSM-5 catalysts and the T 90% of toluene oxidation was only 159 °C .…”

“…19 Recently, our group also found that the ZSM-5 with microporous-mesoporous structure prepared by the organic alkali treatment was beneficial for the dispersion of the noble metal as well as the molecular diffusion of reactants and products, which gave the excellent catalytic activity and thermal stability of Pt/ZSM-5 catalysts for nonchlorinated VOCs oxidation. 20,21 the chlorinated VOCs oxidation (CVOCs), the Pt/ZSM-5 catalysts suffered from the bad activity and stability due to the deactivation by the chlorine species and severe carbon deposition caused by the strong acidity of zeolites. In recent years, many studies have demonstrated that CeO 2 and CeO 2 -MO x (M = Mn, Co, Zr and Ti, etc.)…”

Pt Nanoparticles on Beta zeolites for Catalytic Toluene Oxidation: Effect of the Hydroxyl Groups of Beta Zeolite**

“…Among them, zeolites have been identified as good candidates due to their relatively high surface area, ion‐exchange ability and good thermal stability, as well as the structural flexibility to regulate the metal species (such as the hierarchical zeolites [10–14] ). For example, the hierarchical ZSM‐5 with the micro‐meso‐porous structure could improve the dispersion of Pt species, and thus enhance the toluene oxidation performance [10] . Additionally, by exchanging the charge‐compensating cations in proton‐form Beta zeolite to alkali ions (e. g., Na + and K + ), the resulting supported Pt catalysts showed better toluene oxidation performance due to the formation of more Pt 0 species [15] .…”

“…[5] To promote the performance of Pt-based catalysts, different support materials have been explored to modulate the properties of the supported Pt species (e. g., better dispersion and/or more Pt 0 species) such as Al 2 O 3 , [6] silica, [7] CeO 2 [8] and zeolites. [9] Among them, zeolites have been identified as good candidates due to their relatively high surface area, ion-exchange ability and good thermal stability, as well as the structural flexibility to regulate the metal species (such as the hierarchical zeolites [10][11][12][13][14] ). For example, the hierarchical ZSM-5 with the micro-meso-porous structure could improve the dispersion of Pt species, and thus enhance the toluene oxidation performance.…”