Bimetallic PtSn nanoparticles confined in hierarchical ZSM-5 for propane dehydrogenation

Abstract

A series of PtSn/hierarchical ZSM-5 catalysts were developed for propane dehydrogenation, in which the PtSn bimetallic particles are confined in the mesopores of hierarchical ZSM-5 zeolite. The synthesis of PtSn/hierarchical ZSM-5 catalysts was achieved via the loading of Pt and Sn species onto the hierarchical ZSM-5 catalysts that are obtained through a desilication of conventional ZSM-5. The PtSn/hierarchical ZSM-5 catalysts were fully characterized by XRD, N2 adsorption, STEM, XPS, and CO-IR techniques, which reveals that highly dispersed PtSn bimetallic nanoparticles are enclosed into mesopores of hierarchical ZSM-5. The catalytic performance of PtSn/hierarchical ZSM-5 is greatly affected by the concentrations of alkali solution in the desilication process and Sn/Pt ratios in PtSn bimetallic particles. The PtSn1.00/ZSM-5(0.8) catalyst shows the highest efficiency in propane dehydrogenation, which gives an initial conversion of 46% and selectivity of 98% at 570 °C. The high efficiency in these PtSn/hierarchical ZSM-5 catalysts for propane dehydrogenation is mainly ascribed to the confinement of PtSn particles in the mesopores of hierarchical ZSM-5 zeolite.