SYNTHESIS OF PT@ZSM-5 NANOPARTICLES WITHIN HIERARCHICALLY POROUS ZSM-5/SBA-15 MATERIAL WITH HIGH HYDROGENATION PROPERTY

摘要

Supported noble metal catalysts which are widely used in industrial applications have excellent catalytic performances for gas- phase and liquid-phase reactions. But the interaction of the nanoparticles (NPs) and the support is often not sufficiently strong, and therefore the agglomeration or leaching phenomenon of the catalysts during the reaction is often appear.[1] Encapsulation of noble metal within zeolites can protect such clusters against sintering and also prevent their contact with toxic impurities.[2] The direct encapsulation of metal precursors within zeolites during hydrothermal synthesis process would be a good approach for preparing high stability supported noble metal catalysts. However, the confinement of such metal clusters within small-pore zeolites cannot effectively catalyze large molecules due to the restriction of microporous size. In this research, we confined Pt clusters within small pore ZSM-5 nano-seeds, and further introduce the core-shell Pt@ZSM-5 nano-seeds into mesoporous walls of SBA-15.