Methylation of naphthalene on MTW-type zeolites. Influence of template origin and substitution of Al by Ga

Wu, Wei; Wu, Weiguo; Kikhtyanin, Oleg; Li, Lingfei; Toktarev, Alexander V.; Ayupov, Artem B.; Khabibulin, J.F.; Echevsky, G.V.; Huang, Juan

doi:10.1016/j.apcata.2010.01.003

Cited by 35 publications

(10 citation statements)

References 26 publications

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“…In a zeolite family, the substitution of aluminum atoms by gallium in a silicate matrix leads to the formation of gallium silicates of various structural types whose specific physicochemical properties are successfully used in a number of acid-catalyzed reactions (Fricke et al, 2000 ; Chao and Liu, 2005 ; Wu et al, 2010 ). It is therefore not surprising that a possibility to replace Al atoms by Ga atoms is also assumed in other classes of inorganic compounds.…”

Section: Introductionmentioning

confidence: 99%

Physico-Chemical Properties of MgGa Mixed Oxides and Reconstructed Layered Double Hydroxides and Their Performance in Aldol Condensation of Furfural and Acetone

et al. 2018

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MgGa layered double hydroxides (Mg/Ga = 2–4) were synthesized and used for the preparation of MgGa mixed oxides and reconstructed hydrotalcites. The properties of the prepared materials were examined by physico-chemical methods (XRD, TGA, NH3-TPD, CO2-TPD, SEM, and DRIFT) and tested in aldol condensation of furfural and acetone. The as-prepared phase-pure MgGa samples possessed hydrotalcite structure, and their calcination resulted in mixed oxides with MgO structure with a small admixture phase characterized by a reflection at 2θ ≈ 36.0°. The interaction of MgGa mixed oxides with pure water resulted in reconstruction of the HTC structure already after 15 s of the rehydration with maximum crystallinity achieved after 60 s. TGA-MS experiments proved a substantial decrease in carbonates in all rehydrated samples compared with their as-prepared counterparts. This allowed suggesting presence of interlayer hydroxyls in the samples. Acido-basic properties of MgGa mixed oxides determined by TPD technique did not correlate with Mg/Ga ratio which was explained by the specific distribution of Ga atoms on the external surface of the samples. CO2-TPD method was also used to evaluate the basic properties of the reconstructed MgGa samples. In these experiments, an intensive peak at T = 450°C on CO2-TPD curve was attributed to the decomposition of carbonates newly formed by CO2 interaction with interlayer carbonates rather than to CO2 desorption from basic sites. Accordingly, CO2-TPD method quantitatively characterized the interlayer hydroxyls only indirectly. Furfural conversion on reconstructed MgGa materials was much larger compared with MgGa mixed oxides confirming that Brønsted basic sites in MgGa catalysts, like MgAl catalysts, were active in the reaction. Mg/Ga ratio in mixed oxides influenced product selectivity which was explained by the difference in textural properties of the samples. In contrast, Mg/Ga ratio in reconstructed catalysts had practically no effect on the composition of reaction products suggesting that the basic sites in these catalysts acted similarly in aldol condensation of acetone with furfural. It was concluded that the properties of MgGa samples resembled in a great extent those of MgAl hydrotalcite-based materials and demonstrated their potential as catalysts for base-catalyzed reactions.

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Section: Introductionmentioning

confidence: 99%

Physico-Chemical Properties of MgGa Mixed Oxides and Reconstructed Layered Double Hydroxides and Their Performance in Aldol Condensation of Furfural and Acetone

et al. 2018

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“…Another less intensive band at 3575 cm -1 follows. Its assignment is not conclusive despite the fact that it has been reported for MTW materials in few cases [15,[43][44][45]. Due to its close wavenumber to typical bridging hydroxyls the band in this region is attributed by most researchers to a second kind of bridging hydroxyls.…”

Section: Accepted Manuscriptmentioning

confidence: 90%

Hierarchical MTW zeolites in tetrahydropyranylation of alcohols: Comparison of bottom-up and top-down methods

et al. 2019

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Highlights  Desilication in presence of tetraalkylammonium ions (TAA +) caused pore blockage  Micro-and mesopores can be unblocked by subsequent acid treatment  High fraction of released pores resulted in the limited mass transfer of reactants  In tetrahydropyranylation of alcohols the nanosponge exhibited the highest conversions  In reaction of branched alcohols TAA + desil. zeolites excelled based on TOF values

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“…Compared with poly(ethylene terephthalate) (PET), in addition to its excellent properties as a gas barrier, PEN has good thermal and chemical stability as well as mechanical properties, leading to its wide application in electronics components, insulation material, food containers, aviation, and so on (Song et al, 1993;Tsutsui et al, 2004;Wu et al, 2010;. Highly regioselective synthesis of 2,6-DKN can be achieved over different molecular sieve catalysts using various alkylating agents and solvents (Brzozowski et al, 2012;Liu et al, 1997;Smith et al, 2000;Smith et al, 2003;Smith et al, 2012;Song et al, 2000;Sugi et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…They attributed it to the weakening of the acid strength and the enlargement of the pore dimensions because of the part incorporation of Zr in the framework instead of Al. Wu et al (2010) concluded that the small dimensions of zeolites crystals and the advanced mesoporosity were the general reasons for the remarkable catalytic action of MTW zeolites in naphthalene methylation. Among these molecular sieves, SAPO-11 molecular sieve has been proved to show high catalytic performances in the methylation of naphthalene with methanol (Liu et al, 2013;Wang et al, 2012;Wang et al, 2013;.…”

Section: Introductionmentioning

confidence: 99%

“…As a result, there were great differences in the catalytic activity and selectivity among these molecular sieves (Fraenkel et al, 1986;Park et al, 2002;Jin et al, 2006;Yoo et al, 2002;Jin et al, 2006;Wu et al, 2010). For example, Fraenkel et al (1986) first investigated the methylation of naphthalene with methanol over ZSM-5, mordenite and HY molecular sieves, and found that the medium pore size ZSM-5 showed a high product selectivity and moderate activity, while the large pore size molecular sieves, HY and mordenite, providing enough space for multiple reactions, would lead to a lower product selectivity and a higher activity.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of 2,6-Dimethylnaphthalene Over Sapo-11, Sapo-5 and Mordenite Molecular Sieves

Wang

Liu

Wei

et al. 2017

Braz. J. Chem. Eng.

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-Shape-selective methylation of naphthalene over SAPO-11, SAPO-5 and mordenite molecular sieves were carried out in a fixed-bed flow reactor under atmospheric pressure. Methanol and mesitylene were used as methylation and solvent agents. The experiment results showed that SAPO-11 exhibited higher stability, higher selectivity of 2,6-dimethylnaphthalene (2,6-DMN) and higher 2,6-/2,7-DMN ratio than SAPO-5 and mordenite molecular sieves. The catalytic performances for the methylation of naphthalene were mainly related to the pore structure of the catalysts. The comparison of the spent SAPO-11 with fresh SAPO-11 suggested that structure collapse of the SAPO-11 by dealumination was occurred during the methylation of naphthalene with methanol, which may have been caused by high temperature steam from water produced in the reaction or by high temperature methanol vapor.

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Methylation of naphthalene on MTW-type zeolites. Influence of template origin and substitution of Al by Ga

Cited by 35 publications

References 26 publications

Physico-Chemical Properties of MgGa Mixed Oxides and Reconstructed Layered Double Hydroxides and Their Performance in Aldol Condensation of Furfural and Acetone

Physico-Chemical Properties of MgGa Mixed Oxides and Reconstructed Layered Double Hydroxides and Their Performance in Aldol Condensation of Furfural and Acetone

Hierarchical MTW zeolites in tetrahydropyranylation of alcohols: Comparison of bottom-up and top-down methods

Synthesis of 2,6-Dimethylnaphthalene Over Sapo-11, Sapo-5 and Mordenite Molecular Sieves

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