Characterization of dealuminated large-port mordenites

Niekerk, Miles J. van; Fletcher, J.C.Q.; O’Connor, C.T.

doi:10.1016/0021-9517(92)90014-9

Cited by 32 publications

(9 citation statements)

References 15 publications

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“…Incorporating metal into the SAPO framework has been recognized as a way of improving the olefin selectivity and prolonging the catalyst life time since the reports from Inui and Kang [100,101], as part of the large research efforts on metallosilicates [102][103][104] in his group. Various Me-APSO-34 (Me@Ni [85,101,[105][106][107][108][109][110][111][112][113][114][115][116][117][118][119][120][121], Co, Mn, Fe [106,109,113,114], Cu [79] and Ti, Cr, Cu, Zn, Mg, Ca, Sr, and Ba [119,121]) have been tested in MTO. Incorporating metals into the framework of zeolites has proven to reduce the acid density, leading to a higher selectivity to ethylene, reduced coke formation and thus higher catalyst life time [85,101,121].…”

Section: Effects Of Catalyst Acidity and Composition On Deactivationmentioning

confidence: 99%

A methanol to olefins review: Diffusion, coke formation and deactivation on SAPO type catalysts

Chen

Moljord

Holmén

2012

Microporous and Mesoporous Materials

304

207

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Section: Effects Of Catalyst Acidity and Composition On Deactivationmentioning

confidence: 99%

A methanol to olefins review: Diffusion, coke formation and deactivation on SAPO type catalysts

Chen

Moljord

Holmén

2012

Microporous and Mesoporous Materials

304

207

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“…Subsequently, thin-layer chromatography (TLC) was introduced as a fast and simple identification technique [14], which had to be carried out with great care because of the sensitivity of vitamin E to oxygen. Regarding separations by HPLC, in the beginning (1973) a 1.5 m column packed with pellicular silica gel was employed [16] following by methods using normal and reversed-phase (NP and RP) HPLC [17]. Regarding separations by HPLC, in the beginning (1973) a 1.5 m column packed with pellicular silica gel was employed [16] following by methods using normal and reversed-phase (NP and RP) HPLC [17].…”

Section: Introductionmentioning

confidence: 99%

Analysis of vitamin E in food and phytopharmaceutical preparations by HPLC and HPLC-APCI-MS-MS

et al. 2001

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The analysis of ~, 13, y, 8-tocopheroJs, trienoJs, ~-tocopheryJ acetate and nicotinate (vitamin E) in complex matrices was carried out using a new liquid chromatographic (HPLC) method giving better separation efficiency, selectivity and sensitivity than that described in the literature. The use of normal-phase (NP)-HPLC on silica gel with isooctane-diisopropylether-l,4-dioxane as optimized mobile phase yielded higher resolution than conventional reversed-phase (RP)-HPLC using methanol mobile phase. Identification of peaks was by UV-absorbance at 295 nm, diode array, or fluorescence detection ()~ex = 295 nm, )~ex = 330 nm). The latterwas found to be more selective and ten times more sensitive than UV-absorbance detection. A quadrupole, ion-trap mass spectrometerwith an atmospheric-pressure ionization (APCI) interface was used to detect vitamin E constituents in the femtomole range. With collision-induced dissociation (CID) in the ion source, which gave characteristic fragmentation, the identity of the investigated compounds could be confirmed. Plots of peak area versus amount injected allowed quantitation of ~, 13, y, 8-tocopherols and -trienols, ~-tocopheryl acetate and nicotinate in real samples such as peanut, almond, spinach, spelt grain bran, latex and tablets. The method described offers fast identification and quantitation of vitamin E constituents of complex biological origin.

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“…The hydrothermal conditions used in the dealumination of the ZM samples are conducive to silicon migration, resulting in the replacement of lost aluminum by silicon. This phenomenon stops the unit cell contraction, which was seen for the NM, S1, and S2 samples (van Niekerk et al, 1992), and thus prevents the pore diameters from decreasing. A reduction in unit cell size, and hence pore diameter, as seen in the acid dealuminated samples (van Niekerk et al, 1992) reduces reactant and product diffusivities and results in increased product residence times.…”

Section: Discussionmentioning

confidence: 96%

Methanol Conversion and Propene Oligomerization Productivity of Dealuminated Large-Port Mordenites

Niekerk

O'Connor

Fletcher

1996

Ind. Eng. Chem. Res.

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Four different types of large-port mordenite were studied. Three of these catalyst samples were dealuminated by treatment with nitric acid, and the fourth type was a series of commercially available dealuminated mordenites. The methanol conversion and propene oligomerization productivities and selectivities of these dealuminated mordenites were investigated on a laboratory scale at typical industrial reaction temperatures and pressures. The optimum catalyst morphology and degree of dealumination needed for maximum productivity were found to be similar for both methanol conversion and propene oligomerization. High catalytic productivities were obtained with mordenite which had been hydrothermally dealuminated or with small crystallites which had been synthesized or dealuminated in such a way as to minimize the amount of extra-framework aluminum in the mordenite pores.

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Characterization of dealuminated large-port mordenites

Cited by 32 publications

References 15 publications

A methanol to olefins review: Diffusion, coke formation and deactivation on SAPO type catalysts

A methanol to olefins review: Diffusion, coke formation and deactivation on SAPO type catalysts

Analysis of vitamin E in food and phytopharmaceutical preparations by HPLC and HPLC-APCI-MS-MS

Methanol Conversion and Propene Oligomerization Productivity of Dealuminated Large-Port Mordenites

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