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Defective TiO(x) overlayers catalyze propane dehydrogenation promoted by base metals

Affiliations
  • 1School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China.
  • 2Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China.
  • 3International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China.
  • 4Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China.
  • 5Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
  • 6Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China.
  • 7National Industry-Education Platform of Energy Storage, Tianjin University, Tianjin 300350, China.

Published on:

July 18, 2024

Abstract

The industrial catalysts utilized for propane dehydrogenation (PDH) to propylene, an important alternative to petroleum-based cracking processes, either use expensive metals or metal oxides that are environmentally unbenign. We report that a typically less-active oxide, titanium oxide (TiO), can be combined with earth-abundant metallic nickel (Ni) to form an unconventional Ni@TiO catalyst for efficient PDH. The catalyst demonstrates a 94% propylene selectivity at 40% propane conversion and superior stability under industrially relevant conditions. Complete encapsulation of Ni nanoparticles was allowed at elevated temperatures (>550°C). A mechanistic study suggested that the defective TiO overlayer consisting of tetracoordinated Ti sites with oxygen vacancies is catalytically active. Subsurface metallic Ni acts as an electronic promoter to accelerate carbon-hydrogen bond activation and hydrogen (H) desorption on the TiO overlayer.

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