Direct amination of isobutylene over zeolite catalysts with various topologies and acidities

Gao, Shangyao; Zhu, Xiangxue; Li, Xiujie; Wang, Yu‐Zhong; Xie, Sujuan; Du, Shunda; Chen, Fucun; Zeng, Peng; Liu, Shenglin; Xu, Longya

doi:10.1016/j.jechem.2017.03.018

Cited by 15 publications

(12 citation statements)

References 34 publications

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“…The justification for using this expression is discussed below. The results presented in Figure are very similar to those reported by Mizuno et al and Gao et al, the activity per Brønsted acid site decreasing in the order of MFI > MWW > MOR > FAU > FER. , …”

Section: Resultsmentioning

confidence: 99%

“…The results presented in Figure 2 are very similar to those reported by Mizuno et al and Gao et al, the activity per Brønsted acid site decreasing in the order of MFI > MWW > MOR > FAU > FER. 10,19 To make a more accurate comparison of catalytic activity, the measured rates must be normalized by the number of active sites. Although Brønsted acidic protons have been identified as the active site for alkene amination in zeolites, not all protons may be accessible.…”

Section: ■ Experimental Methodsmentioning

confidence: 99%

“…They proposed that acid site density and acid strength were both critical factors for the reaction. Gao et al have observed a similar dependence between isobutene conversion and Si/Al ratio; however, they interpreted their findings on the basis of variations in Brønsted acid site density . The framework also appears to play an important role in the reaction.…”

Section: Introductionmentioning

confidence: 96%

“…The framework also appears to play an important role in the reaction. For a given Si/Al ratio, large differences in the reaction rate and activation energy are observed depending on the framework. ,, Small-pored zeolites are inactive because t -BuNH 2 is too bulky to fit within the pores. However, the effect of pore geometry and connectivity on the turnover frequency has not been established.…”

Section: Introductionmentioning

confidence: 99%

“…Gao et al have observed a similar dependence between isobutene conversion and Si/Al ratio; however, they interpreted their findings on the basis of variations in Brønsted acid site density. 19 The framework also appears to play an important role in the reaction. For a given Si/Al ratio, large differences in the reaction rate and activation energy are observed depending on the framework.…”

Section: ■ Introductionmentioning

confidence: 99%

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Zeolite-Catalyzed Isobutene Amination: Mechanism and Kinetics

Bettinson

Choi

et al. 2019

ACS Catal.

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Amination of isobutene with NH 3 was investigated over Brønsted acidic zeolites at 1 atm and 453−483 K. To compare catalytic activities over different zeolites, the measured reaction rates are normalized by the number of active sites determined by tert-butylamine temperature-programmed desorption (TPD). Small-and medium-pore zeolites with one-dimensional channels exhibit low activity because of pore blockage by adsorbed tertbutylammonium ions. However, turnover frequencies and activation energies are not sensitive to framework identity, as long as the active site is accessible to isobutene and tertbutylamine. Kinetic measurements and FTIR spectroscopy reveal that the Brønsted acid sites in MFI are covered predominantly with tert-butylammonium ions under reaction conditions. The desorption of tert-butylamine is assisted by the concurrent adsorption of isobutene. DFT simulations show that at very low tert-butylamine partial pressures, for example, at the inlet to the reactor, tert-butylamine desorption is rate-limiting. However, at sufficiently high tert-butylamine partial pressures (>0.03 kPa), protonation of isobutene to the corresponding carbenium ion limits the rate of amination.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Experimental Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Zeolite-Catalyzed Isobutene Amination: Mechanism and Kinetics

Bettinson

Choi

et al. 2019

ACS Catal.

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Laser‐assisted preparation of monolithic acidic catalysts for biomass conversion

Cao

Tao

2022

AIChE Journal

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5‐(Hydroxymethyl)furfural (5‐HMF) is a vital platform molecule from which a variety of high‐value‐added fine chemicals and polymerizable monomers can be prepared. The use of solid acids to catalyze the conversion of biomass into 5‐HMF is environmentally friendly and economical. However, exploiting the high yield of 5‐HMF in a highly concentrated reactant system is challenging. Herein, we present a laser‐assisted method for preparing highly acidic monolithic acidic catalysts. A monolithic acidic catalyst based on metal Zr sheets was synthesized and used to catalytically convert 30 wt% fructose into 5‐HMF (conversion rate: 96%; yield: 95%). The catalyst was immediately separated from the reaction solution by direct removal at the end of the reaction. Catalytic efficiency was largely unaffected after 10 cycles of use, and the same catalytic efficiency was observed after laser‐regeneration, highlighting the potential industrial applicability of the developed catalyst.

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