Following Solid-Acid-Catalyzed Reactions by MAS NMR Spectroscopy in Liquid Phase-Zeolite-Catalyzed Conversion of Cyclohexanol in Water

Acid catalysis is widely used in the chemical industry, and nowadays many efforts are being focused on replacing the more common homogeneous catalysts with heterogeneous ones in order to make greener the industrial processes. In this perspective, sulfonic solid acid materials represent a valid alternative to the homogenous mineral acid in several acid catalyzed reactions. In this minireview, an overview of the recent advances on the preparation, stability and application of these materials is reported. Special attention is addressed to the sustainability of the considered processes, starting from the catalyst’s preparation, the use of green solvents and reducing the possible reaction steps. Ways to tackle the main drawback represented by easy leaching of acid groups are described. For an easy catalyst recovery, the use of a magnetic core in a catalyst particle, with the related synthetic approaches, is also illustrated. Finally, a section is dedicated to the principal characterization techniques to identify the structural properties of the catalysts.

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Development of catalyst materials for acid-catalyzed reactions in the liquid phase

Catalysis Today ◽

10.1016/s0920-5861(96)00126-5 ◽

1997 ◽

Vol 35 (1-2) ◽

pp. 183-188 ◽

Cited By ~ 14

Author(s):

Y. Izumi ◽

K. Urabe ◽

M. Onaka

Keyword(s):

Liquid Phase ◽

Acid Catalyzed ◽

Catalyzed Reactions

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Catalysis by Heteropoly Compounds. (Part 24). Acid-catalyzed Reactions in Liquid-phase over Solid Heteropolyacids Having Tungsten as Addenda Atom-Effects of Central Atom.

Journal of The Japan Petroleum Institute ◽

10.1627/jpi1958.36.386 ◽

1993 ◽

Vol 36 (5) ◽

pp. 386-393 ◽

Cited By ~ 11

Author(s):

Changwen HU ◽

Toru NISHIMURA ◽

Toshio OKUHARA ◽

Makoto MISONO

Keyword(s):

Liquid Phase ◽

Central Atom ◽

Heteropoly Compounds ◽

Acid Catalyzed ◽

Catalyzed Reactions

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Photoinduced rearrangement of hydroxymethylisoxazolines, a route to enaminoaldehydes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19862167 ◽

1986 ◽

Vol 51 (10) ◽

pp. 2167-2180 ◽

Cited By ~ 6

Author(s):

Lubor Fišera ◽

Nadezhda D. Kozhina ◽

Peter Oravec ◽

Hans-Joachim Timpe ◽

Ladislav Štibrányi ◽

...

Keyword(s):

Thionyl Chloride ◽

Quantum Yields ◽

Acid Catalyzed ◽

Catalyzed Reactions ◽

Photoinduced Rearrangement ◽

Condensed Heterocycles

3-Aryl-4-R-carbamoyl-5-hydroxymethylisoxazolines (IV) were synthesized by allowing R-NH2 amines with R = H, CH3, C3H7, C6H5C2H5, and NH2 to act on 3-(X-phenyl)-4-oxo-3a,4,6,6a-tetrahydrofuro[3,4-d]isoxazoles (III) with X = H, 4-CH3, 4-OCH3, 2-OCH3, 4-Cl, 2-Cl, 4-F, 2-F, 4-Br, 4-NO2, and 3-NO2. Exposed to radiation, the substances IV give Z-2-hydroxymethylamino-2-aryl-1-formylacrylamides (V) in good yields. The 4-Cl and 4-F substituted Z-derivatives V isomerize irreversibly to the E-derivatives VI if allowed to stand in solvent; the remaining derivatives V are stable. The quantum yields of the photoreaction are from 0.012 to 0.106 in dependence on the substituent X. In all cases where the compounds IV were used for the preparation of condensed heterocycles in conditions of acid-catalyzed reactions, lactones III were preferentially formed; the action of thionyl chloride on IV results in the formation of chloromethyl derivatives VIII, which do not undergo further cyclization.

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Synthetic Scope of Brønsted Acid-Catalyzed Reactions of Carbonyl Compounds and Ethyl Diazoacetate

The Journal of Organic Chemistry ◽

10.1021/acs.joc.0c02972 ◽

2021 ◽

Author(s):

Mizzanoor Rahaman ◽

M. Shahnawaz Ali ◽

Khorshada Jahan ◽

Damon Hinz ◽

Jawad Bin Belayet ◽

...

Keyword(s):

Carbonyl Compounds ◽

Bronsted Acid ◽

Brønsted Acid ◽

Ethyl Diazoacetate ◽

Brönsted Acid ◽

Acid Catalyzed ◽

Catalyzed Reactions

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Hierarchical HZSM-5 for Catalytic Cracking of Oleic Acid to Biofuels

Nanomaterials ◽

10.3390/nano11030747 ◽

2021 ◽

Vol 11 (3) ◽

pp. 747

Author(s):

Mahashanon Arumugam ◽

Chee Keong Goh ◽

Zulkarnain Zainal ◽

Sugeng Triwahyono ◽

Adam F. Lee ◽

...

Keyword(s):

Oleic Acid ◽

Solid Acid ◽

High Surface ◽

High Surface Area ◽

Acid Catalyst ◽

Hierarchical Network ◽

Waste Oil ◽

Acid Catalyzed ◽

Zeolite Seeds ◽

20 Nm

Solid acid catalyzed cracking of waste oil-derived fatty acids is an attractive route to hydrocarbon fuels. HZSM-5 is an effective acid catalyst for fatty acid cracking; however, its microporous nature is susceptible to rapid deactivation by coking. We report the synthesis and application of hierarchical HZSM-5 (h-HZSM-5) in which silanization of pre-crystallized zeolite seeds is employed to introduce mesoporosity during the aggregation of growing crystallites. The resulting h-HZSM-5 comprises a disordered array of fused 10–20 nm crystallites and mesopores with a mean diameter of 13 nm, which maintain the high surface area and acidity of a conventional HZSM-5. Mesopores increase the yield of diesel range hydrocarbons obtained from oleic acid deoxygenation from ~20% to 65%, attributed to improved acid site accessibility within the hierarchical network.

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