Subnanometer Bimetallic Platinum-Zinc Clusters in Zeolites for Propane Dehydrogenation.
Angew Chem Int Ed Engl
; 59(44): 19450-19459, 2020 Oct 26.
Article
em En
| MEDLINE
| ID: mdl-32259339
ABSTRACT
Propane dehydrogenation (PDH) has great potential to meet the increasing global demand for propylene, but the widely used Pt-based catalysts usually suffer from short-term stability and unsatisfactory propylene selectivity. Herein, we develop a ligand-protected direct hydrogen reduction method for encapsulating subnanometer bimetallic Pt-Zn clusters inside silicalite-1 (S-1) zeolite. The introduction of Zn species significantly improved the stability of the Pt clusters and gave a superhigh propylene selectivity of 99.3 % with a weight hourly space velocity (WHSV) of 3.6-54â
h-1 and specific activity of propylene formation of 65.5â
mol C 3 H 6 gPt -1 h-1 (WHSV=108â
h-1 ) at 550 °C. Moreover, no obvious deactivation was observed over PtZn4@S-1-H catalyst even after 13000â
min on stream (WHSV=3.6â
h-1 ), affording an extremely low deactivation constant of 0.001â
h-1 , which is 200â
times lower than that of the PtZn4/Al2 O3 counterpart under the same conditions. We also show that the introduction of Cs+ ions into the zeolite can improve the regeneration stability of catalysts, and the catalytic activity kept unchanged after four continuous cycles.
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MEDLINE
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En
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Angew Chem Int Ed Engl
Ano de publicação:
2020
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Article