Use of solid catalysts in Friedel-Crafts acylation reactions.

Catalytic conversion of glucose to 5-hydroxymethylfurfural over SO42−/ZrO2 and SO42−/ZrO2–Al2O3 solid acid catalysts

A solid acid material of high loading of sulfated zirconia on mesoporous silica SBA-15 has been successfully synthesized by a direct-synthesis under strong acidic condition. The materials were characterized by powder X-ray diffraction, N2 adsorption−desorption, UV−visible diffuse reflectance spectroscopy, transmission electron microscopy (TEM), ICP-mass, and NH3 temperature-programmed-desorption (TPD). The zirconia content and well-ordered mesostructure of SiO2−SZ are controllable by tuning the molar ratios of sulfate to zirconia and silica to zirconia. UV−visible spectra and TEM observations confirm the incorporation of zirconium (IV) onto the mesoporoes framework. Acidity is enhanced in comparison with unsupported sulfated zirconia. Much improved catalytic performance under mild temperature condition in the esterification of lauric acid and palmitic acid with the direct-synthesis SiO2−SZ catalyst was observed as compared to un-supported SZ. The good catalytic performance of the sulfated silica-zirconia ...

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Direct Synthesis of Mesoporous Sulfated Silica-Zirconia Catalysts with High Catalytic Activity for Biodiesel via Esterification

Conventional (per)sulfated bulk zirconia, mesoporous sulfated zirconia and (per)sulfated zirconia supported on an ordered mesoporous silica, with or without aluminium incorporation, were examined as acid catalysts for the dehydrocyclisation of xylose into furfural. Furfural yields of up to 50% could be achieved at >90% conversion with the modified zirconia catalysts, which is better than that achievable with H2SO4 (using approximately the same equivalent amount of sulfur.)

Modified versions of sulfated zirconia as catalysts for the conversion of xylose to furfural

Update 1 of: Use of Solid Catalysts in Friedel Crafts Acylation Reactions Giovanni Sartori* and Raimondo Maggi Clean Synthetic Methodologies Group and National Interuniversity Consortium “Chemistry for Environment” (INCA), Unit PR2, Dipartimento di Chimica Organica e Industriale, Universit a degli Studi di Parma, Parco Area delle Scienze 17A, I-43100 Parma, Italy This is a Chemical Reviews Perennial Review. The root paper of this title was published in Chem. Rev. 2006, 106 (3), 1077 1104, DOI: 10.1021/cr040695c; Published (Web) February 14, 2006. Updates to the text appear in red type.

Update 1 of: Use of Solid Catalysts in Friedel−Crafts Acylation Reactions

Mesoporous sulfated zirconia (MP-ZrO2) were synthesized hydrothermally using Zr(O-nPr)4 as zirconium precursor, ammonium sulfate as sulfur source and CTABr as template. Then the as-synthesized mesoporous materials were directly impregnated with aluminum sulfate to give the acidic Al-promoted mesoporous sulfated zirconia. (AS/MP-ZrO2). The AS/MP-ZrO2 catalyst was characterized by nitrogen physisorption (BET) for texture properties, by X-ray diffraction (XRD) for confirming the phase and by TEM for particle sizes. The catalytic conversion of n-butane isomerization was measured in a flow reactor. With the addition of a proper amount of aluminum as a promoter, the catalytic behavior for n-butane isomerization at low temperature in flow system was strongly promoted. The increase of activity was determined primarily by the amount of alumina addition and by the temperature of calcination. The highest catalytic performance is for the catalyst prepared at an optimum 3 mol.% Al loading and calcination at 650 °C. The nature of the acidic sites was determined by X-ray photoelectron spectroscopy (XPS) measurements of N 1 s of the adsorbed pyridine. Three kinds of acid sites were identified on the catalyst: a Lewis site, a weak Bronsted site and a strong Bronsted site. The catalytic activities are correlated with the amount of weak Bronsted acid sites. The remarkable activity and stability of the Al-promoted catalysts are due to a balanced distribution of acid sites strength with an enhanced amount of weak Bronsted acid sites.

Jung-Hui Wang

Papers

Alumina-promoted mesoporous sulfated zirconia: A catalyst for n-butane isomerization

Characterizations of aluminum-promoted sulfated zirconia on mesoporous MCM-41 silica: Butane isomerization

n-Pentane isomerization over promoted SZ/MCM-41 catalysts

Strongly acidic mesoporous aluminosilicates prepared from zeolite seeds: acylation of anisole with octanyl chloride

Catalytic behavior of nanostructured sulfated zirconia promoted by alumina : Butane isomerization