PtZn Intermetallic Alloys Dispersed on Ceria Islands inside Mesoporous Zeolite for Propane Dehydrogenation Catalyst

A propane dehydrogenation (PDH) catalyst with 0.5 wt % Pt, 0.5 wt % Zn, and 2 wt % Ce was prepared by impregnating an aqueous solution of H2PtCl6, Zn(NO3)2, and Ce(NO3)3 into a hierarchically microporous-mesoporous zeolite built with a siliceous MFI framework. The PtZnCe/zeolite exhibited a high catalytic performance for propane dehydrogenation to propylene, even at high space velocities. The catalyst could be calcined in air at 580 °C for regeneration without the risk of Pt agglomeration. Analyses using scanning transmission electron microscopy indicated that the high PDH performance came from 1:1 stoichiometric PtZn intermetallic compound-type alloy nanoparticles, which were dispersed on the surface of ceria islands confined in the zeolite mesopore. The mesopore-confined ceria effectively stabilized these nanoparticles through strong metal–support interactions, enabling high dispersion under severe reaction conditions.