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- W2594855509 abstract "The selective epoxidation of olefins with hydrogen peroxide (H2O2) over transition metal substituted zeolites is less environmentally impactful than epoxidation schemes that use chlorinated or organic oxidants. The structure and reactivity of reactive intermediates derived from H2O2 and the mechanism for olefin epoxidation on such materials are debated. Here, cyclohexene oxide formation and H2O2 decomposition rates (measured as functions of reactant and product concentrations) and in situ infrared (IR) and UV-vis spectroscopy are used to probe the intervening elementary steps for cyclohexene (C6H10) epoxidation and the identity of the reactive intermediates on a Nb-β catalyst. IR and UV-vis spectra acquired in situ show that the reactive intermediates are predominantly superoxide species (NbIV-(O2)−, observed also by X-ray photoelectron spectroscopy), which form by the irreversible activation of H2O2 over Nb centers. Similar M-(O2)∗ (M = Ti or Ta) intermediates were previously assumed to form via reversible processes; however, in situ IR and UV-vis measurements directly show that NbIV-(O2)− forms irreversibly in both H2O and acetonitrile. Activation enthalpies (ΔH‡) for C6H10 epoxidation are 27 kJ mol−1 higher than for H2O2 decomposition, while activation entropies (ΔS‡) for epoxidation are 56 J mol−1 K−1 lower than for H2O2. These comparisons show that the selectivities for epoxidation, via primary reaction pathways, increase with increasing reaction temperatures. Collectively, these results provide a self-consistent mechanism for C6H10 epoxidation that is also in agreement with previously published data. These findings will aid the rational design and study of alternative metal oxide catalysts for olefin oxidation reactions." @default.
- W2594855509 created "2017-03-16" @default.
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- W2594855509 date "2017-04-01" @default.
- W2594855509 modified "2023-09-26" @default.
- W2594855509 title "Kinetic and spectroscopic evidence for reaction pathways and intermediates for olefin epoxidation on Nb in *BEA" @default.
- W2594855509 cites W1936344293 @default.
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- W2594855509 cites W1974187134 @default.
- W2594855509 cites W1974877410 @default.
- W2594855509 cites W1975077437 @default.
- W2594855509 cites W1976243220 @default.
- W2594855509 cites W1983230556 @default.
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- W2594855509 cites W1989416110 @default.
- W2594855509 cites W1990657317 @default.
- W2594855509 cites W1995834650 @default.
- W2594855509 cites W2000162773 @default.
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- W2594855509 cites W2008256766 @default.
- W2594855509 cites W2008560502 @default.
- W2594855509 cites W2009549694 @default.
- W2594855509 cites W2023138802 @default.
- W2594855509 cites W2023678176 @default.
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- W2594855509 doi "https://doi.org/10.1016/j.jcat.2017.02.008" @default.
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