The di-t-butylation of p-cresol with t-butanol in supercritical CO2 over tungstophosphoric acid supported on ordered mesoporous silica

• Published in: Catalysis letters Vol. 108; no. 1-2; pp. 31 - 35
• Main Authors: KAMALAKAR, G, KOMURA, Kenichi, SUGI, Yoshihiro
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.04.2006; Springer Nature B.V
• Subjects: Butanol; Carbon dioxide; Catalysis; Catalysts; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Liquid phases; Pore size; Porosity; Porous materials; Silicon dioxide; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Thermogravimetric analysis; Zeolites; Tungstophosphoric acid; Support; 2,6-di-t-butyl-4-methylphenol; Alcohol; supercritical CO2; MCM-41; Supercritical state; Porous material; Silica; Alkylation; Supported catalyst; Mesoporosity; Cresol; Heterogeneous catalysis; t-butylation; Acids; p-cresol; Alkanol; Phenols; Benzenic compound; Butanol
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-006-0032-z

Tungstophosphoric acid (HPW) supported on MCM-41 was an excellent catalyst for the t-butylation of p-cresol to 2,6-di-t-butyl-4-methylphenol (2,6-DTBPC) in supercritical CO2; however, zeolites, H-Y and H-Beta, only gave 2-t-butyl-4-methylphenol (2-TBPC) because of their limitation in pore size. The yield of 2,6-DTBPC was maximized at 110 °C, and further increase in temperature rather decreased the yield. The yield of 2,6-DTBPC was maximized at 10–11 MPa CO2 pressure, and further increase of the pressure decreased in the conversion of phenol and the yield of 2,4-DTBC. The thermogravimetric analysis of used catalysts showed that the coke-formation was minimized in supercritical CO2 compared to the other reaction media such as in liquid phase and in N2 atmosphere.