In situ formation of ZnOx species for efficient propane dehydrogenation

• Published in: Nature (London) Vol. 599; no. 7884; pp. 234 - 238
• Main Authors: Zhao, Dan, Tian, Xinxin, Doronkin, Dmitry E., Han, Shanlei, Kondratenko, Vita A., Grunwaldt, Jan-Dierk, Perechodjuk, Anna, Vuong, Thanh Huyen, Rabeah, Jabor, Eckelt, Reinhard, Rodemerck, Uwe, Linke, David, Jiang, Guiyuan, Jiao, Haijun, Kondratenko, Evgenii V.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 11.11.2021; Nature Publishing Group UK
• Subjects: Aluminum oxide; Biocompatibility; Catalysts; Chlorine; Chlorine compounds; Chromium; Dehydrogenation; Hexavalent chromium; Metal oxides; Nanoparticles; Propane; Selectivity; Silicalite; Species; Spectrum analysis; Toxicity; Zeolites; Zinc; Zinc oxide
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/s41586-021-03923-3

Abstract Propane dehydrogenation (PDH) to propene is an important alternative to oil-based cracking processes, to produce this industrially important platform chemical 1,2 . The commercial PDH technologies utilizing Cr-containing (refs. 3,4 ) or Pt-containing (refs. 5–8 ) catalysts suffer from the toxicity of Cr( vi ) compounds or the need to use ecologically harmful chlorine for catalyst regeneration 9 . Here, we introduce a method for preparation of environmentally compatible supported catalysts based on commercial ZnO. This metal oxide and a support (zeolite or common metal oxide) are used as a physical mixture or in the form of two layers with ZnO as the upstream layer. Supported ZnO x species are in situ formed through a reaction of support OH groups with Zn atoms generated from ZnO upon reductive treatment above 550 °C. Using different complementary characterization methods, we identify the decisive role of defective OH groups for the formation of active ZnO x species. For benchmarking purposes, the developed ZnO–silicalite-1 and an analogue of commercial K–CrO x /Al 2 O 3 were tested in the same setup under industrially relevant conditions at close propane conversion over about 400 h on propane stream. The developed catalyst reveals about three times higher propene productivity at similar propene selectivity.