Insight into Three‐Coordinate Aluminum Species on Ethanol‐to‐Olefin Conversion over ZSM‐5 Zeolites. Issue 50 (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 international edition. Volume 58:Issue 50(2019)
• Page Start: 18061
• Page End: 18068
• Publication Date: 2019-10-30
• Subjects: acidity -- aluminum -- ethanol to olefin -- MFI zeolite -- solid-state NMR spectroscopy; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201910987
• Languages: English
• ISSNs: 1433-7851

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 : Three's company : Three‐coordinate Al 3+ species working with Brønsted acid sites can accelerate bioethanol dehydration from >9 h to 1–2 h at the much lower reaction temperature and a short unsteady‐state period.