Ultrastable Pt/Zn-Doped-Al<sub>2</sub>O<sub>3</sub> Catalyst for Propane Dehydrogenation

Propane dehydrogenation (PDH) is a crucial and effective\ntechnology\nto produce propylene industrially and is in great demand around the\nglobe. Silica/zeolite-supported PtZn bimetallic catalysts have been\nreported to exhibit long-term operation and a consecutive regeneration\nprocess at high temperatures. However, over the industrially most\ncommonly used support Al<sub>2</sub>O<sub>3</sub>, PtZn bimetallic\nnanoparticles suffer from low stability. Herein, we develop Zn-doped\nAl<sub>2</sub>O<sub>3</sub> (ZnAlO<sub><i>x</i></sub>) to\nstabilize PtZn nanoparticles (<1 nm) for the PDH reaction, for\nwhich the structure and composition of the PtZn intermetallic nanoparticles\ncould be controlled by tuning the ratio of Zn/Al. The optimized catalyst\nwith Zn/Al = 1/5 (mole ratio) exhibited the most remarkable stability\nwith an extremely low <i>k</i><sub>d</sub> value of 0.0007\nh<sup>–1</sup> and survived 10 cycles of regeneration tests\nwith negligible deactivation. Characterizations by HAADF-STEM, XAS,\nand XRD, together with in situ XPS and CO-DRIFTS, proved that the\nexcellent performance originated from the Pt<sub>1</sub>Zn<sub>1</sub> intermetallic compound formed during the reaction and the enhanced\ninteraction between the Pt<sub>1</sub>Zn<sub>1</sub> nanoparticles\nand the Zn-doped Al<sub>2</sub>O<sub>3</sub> support.