Insight into Three‐Coordinate Aluminum Species on Ethanol‐to‐Olefin Conversion over ZSM‐5 Zeolites. (30th October 2019)

• Record Type: Journal Article
• Authors: Wang, Zichun; O'Dell, Luke A.; Zeng, Xin; Liu, Can; Zhao, Shufang; Zhang, Wenwen; Gaborieau, Marianne; Jiang, Yijiao; Huang, Jun
• Is Part Of: Angewandte Chemie. Volume 131:Number 50(2019)
• Page Start: 18229
• Page End: 18236
• Publication Date: 2019-10-30
• Subjects: Acidität -- Aluminum -- Ethanol-zu-Olfein-Umwandlung -- Festkörper-NMR -- MFI-Zeolithe; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201910987
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Commercial bioethanol can be readily converted into ethylene by a dehydration process using solid acids, such as Brønsted acidic H‐ZSM‐5 zeolites, and thus, it is an ideal candidate to replace petroleum and coal for the sustainable production of ethylene. Now, strong Lewis acidic extra‐framework three‐coordinate Al 3+ species were introduced into H‐ZSM‐5 zeolites to improve their catalytic activity. Remarkably, Al 3+ species working with Brønsted acid sites can accelerate ethanol dehydration at a much lower reaction temperature and shorten the unsteady‐state period within 1–2 h, compared to >9 h for those without Al 3+ species, which can significantly enhance the ethanol dehydration efficiency and reduce the cost. The reaction mechanism, studied by solid‐state NMR, shows that strong Lewis acidic EFAl‐Al 3+ species can collaborate with Brønsted acid sites and promote ethanol dehydration either directly or indirectly via an aromatics‐based cycle to produce ethylene. Abstract : Alle guten Dinge sind drei : Dreifach koordinierte Al 3+ ‐Spezies können in Zusammenarbeit mit Brønsted‐sauren Zentren die Dehydration von Bioethanol von über 9 h auf 1–2 h beschleunigen. Dies geschieht bei einer deutlich geringeren Reaktionstemperatur und verkürzten Dauer im nicht‐stationären Zustand.