Propane Dehydrogenation over Pt Clusters Localized at the Sn Single-Site in Zeolite Framework

Abstract

Catalytic dehydrogenation of propane over a Pt-based catalyst to propylene has received considerable interests in recent years because this route is able to provide an economical and efficient way to fill the gap between supply and demand in propylene market. The low dispersion of a Pt particle at the support surface and sintering of Pt nanoparticles under the harsh reaction condition are the main challenges in the practical application of this catalyst. Herein, highly efficient Pt/Sn-Beta catalysts are developed for propane dehydrogenation, which exhibits high activity, selectivity, and stability in this reaction. Full characterizations with XRD, STEM, XPS, CO-IR, H2-TPR, and Py-IR techniques on these catalysts reveal that the Pt clusters are localized at the Sn single-site in the zeolitic framework, which allows the generated Pt clusters to be homogeneously dispersed at the surface zeolite. The high performance of Pt/Sn-Beta catalysts under a high reaction temperature is mainly due to a strong interaction between the Pt cluster and Sn-zeolite. An initial propane conversion of 50%, high propylene selectivity of above 99%, low deactivation rate of 0.006 h–1, high TOF of 114 s–1, and good regenerability have been achieved in the Pt-Sn2.00/Sn-Beta catalyst for propane dehydrogenation at 570 °C.