Wu X, Zhang Z, Pan Z, Zhou X, Bodi A, Hemberger P. Ketenes in the Induction of the Methanol-to-Olefins Process.
Angew Chem Int Ed Engl 2022;
61:e202207777. [PMID:
35929758 PMCID:
PMC9804150 DOI:
10.1002/anie.202207777]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Indexed: 01/05/2023]
Abstract
Ketene (CH2 =C=O) has been postulated as a key intermediate for the first olefin production in the zeolite-catalyzed chemistry of methanol-to-olefins (MTO) and syngas-to-olefins (STO) processes. The reaction mechanism remains elusive, because the short-lived ethenone ketene and its derivatives are difficult to detect, which is further complicated by the low expected ketene concentration. We report on the experimental detection of methylketene (CH3 -CH=C=O) formed by the methylation of ketene on HZSM-5 via operando synchrotron photoelectron photoion coincidence (PEPICO) spectroscopy. Ketene is produced in situ from methyl acetate. The observation of methylketene as the ethylene precursor evidences a computationally predicted ketene-to-ethylene route proceeding via a methylketene intermediate followed by decarbonylation.
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