Characterization of the actual catalytic agent in potassium fluoride on activated alumina systems

Weinstock, Leonard M.; Stevenson, James; Tomellin, Sterling A.; Pan, Shih-hsie; Utne, Torleif; Jobson, Ronald B.; Reinhold, Donald F.

doi:10.1016/s0040-4039(00)83895-2

Cited by 73 publications

(53 citation statements)

References 15 publications

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“…The above results indicate that the KF loaded can react with c-Al 2 O 3 and H 2 O to form K 3 AlF 6 and KOH (reaction 1). This conclusion is consistent with that reported by Weinstock et al [23]. Moreover, it can be seen from Fig.…”

Section: Active Species On Kf/c-al 2 Osupporting

confidence: 94%

Characterization of KF/γ-Al2O3 Catalyst for the Synthesis of Diethyl Carbonate by Transesterification of Ethylene Carbonate

Qiu

Yang

et al. 2010

Catal Lett

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KF/c-Al 2 O 3 catalysts were prepared by impregnation method and investigated for the transesterification of ethylene carbonate (EC) with ethanol to synthesize diethyl carbonate (DEC). The KF/c-Al 2 O 3 catalysts were characterized by nitrogen physisorption, XRD and FT-IR techniques, and three new species: K 3 AlF 6 , KOH and K 2 CO 3 were found on the catalysts. Experimental results indicate that KOH and K 2 CO 3 are the major active species and K 3 AlF 6 is inactive for DEC synthesis. Increasing the KF loading favors the formation of K 2 CO 3 and consequently enhances the activity of the KF/c-Al 2 O 3 catalysts. However, when KF loading exceeded 50 mmol/g, the activity of the KF/c-Al 2 O 3 catalysts decreased. This may be due to the presence of intact KF on the catalyst, which may dilute the content of active species in the catalyst and cover the active species. The KF/c-Al 2 O 3 (50 mmol/g) catalyst exhibits the best catalytic performance. With this catalyst, a 72 mol% yield of DEC (based on EC) was obtained at 298 K.

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Section: Active Species On Kf/c-al 2 Osupporting

confidence: 94%

Characterization of KF/γ-Al2O3 Catalyst for the Synthesis of Diethyl Carbonate by Transesterification of Ethylene Carbonate

Qiu

Yang

et al. 2010

Catal Lett

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“…This observation validates the role of participation of active sites from the catalyst in addition with that from its physical constituent's alumina and KF in the overall activity of the reaction. This might be due to the hydroxide species formed by the interaction between KF and alumina [29]. The catalyst activated at 300°C showed nearly the same activity as that of as synthesized catalyst.…”

Section: Catalytic Activitymentioning

confidence: 83%

“…The main active constituents in the KF/Al 2 O 3 are K ? , F -, OH -and Al-[OHÁÁÁF] - [28][29][30][31][32]. The ionic species; K ?…”

Section: Catalytic Activitymentioning

confidence: 99%

Transesterification of Propylene Carbonate by Methanol Using KF/Al2O3 as an Efficient Base Catalyst

2010

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Dimethyl carbonate was synthesized via transesterification of propylene carbonate by methanol using KF/Al 2 O 3 as base catalyst. The catalyst was characterized using FT-IR, XRD, surface area measurement, alkalinity measurement and SEM analysis. The effect of KF loading on Al 2 O 3 , reaction parameters such as reaction temperature, reactant ratio and amount of catalyst on the product yield were investigated. It was found that the catalyst with 20 wt% KF loading on neutral alumina showed 70.9% propylene carbonate conversion with [98% DMC selectivity.

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“…For the KF/ZnO catalyts, the intensity of the band at 1640 cm )1 which is due to the bending vibration of water molecular, became weaker and finally disappeared with the increase of calcination temperature, which indicates gradual loss of physisorbed water. It has been proposed that KF could simply introduce hydroxyls at the surface of alumina, and this hypothesis was investigated by infrared spectrometry on KF/Al 2 O 3 samples [30]. ZnO has practically no hydroxyls, whereas KF/ZnO has a strong OH band at 3350 cm )1 as illustrated in figure 3, even after calcination at 573 K. This O-H band absorption was not totally attributed to the stretching vibration of water molecular but partly assigned to the absorption of surface hydroxyl groups, because it still remained and even became stronger when the absorption peak at 1640 cm )1 due to water bending vibration became weaker and even disappeared.…”

Section: Ftir Analysismentioning

confidence: 99%

Synthesis of Biodiesel from Soybean Oil using Heterogeneous KF/ZnO Catalyst

2006

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Biodiesel was produced by transesterification of soybean oil with methanol using ZnO loaded with KF as a solid base catalyst. It was found that the catalyst with 15 wt.% KF loading and calcined at 873 K showed the optimum activity. XRD, IR and Hammett indicator method were employed for the catalyst characterization. The results showed the activity of the catalysts was correlated with their basicity. The influence of various reaction variables on the conversion was also discussed.

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Characterization of the actual catalytic agent in potassium fluoride on activated alumina systems

Cited by 73 publications

References 15 publications

Characterization of KF/γ-Al2O3 Catalyst for the Synthesis of Diethyl Carbonate by Transesterification of Ethylene Carbonate

Characterization of KF/γ-Al2O3 Catalyst for the Synthesis of Diethyl Carbonate by Transesterification of Ethylene Carbonate

Transesterification of Propylene Carbonate by Methanol Using KF/Al2O3 as an Efficient Base Catalyst

Synthesis of Biodiesel from Soybean Oil using Heterogeneous KF/ZnO Catalyst

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