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Alkylation of p-cresol with tert-butanol catalyzed by heteropoly acid supported on zirconia catalyst

2003; Elsevier BV; Volume: 210; Issue: 1-2 Linguagem: Inglês

10.1016/j.molcata.2003.09.015

1873-314X

Biju M. Devassy, Ganapati V. Shanbhag, F. Lefebvre, S.B. Halligudi,

Metal-Organic Frameworks: Synthesis and Applications

Butylation of p-cresol by tert-butanol was catalyzed by 12-tungstophosphoric acid supported on zirconia (TPA/ZrO2) under flow conditions. Catalysts prepared with different TPA loading (5–30 wt.%) were calcined at 1023 K and acidity was estimated by temperature programmed desorption (TPD) of NH3. Fifteen percent TPA/ZrO2 showed the highest acidity and found to be the most active catalyst in butylation of p-cresol. The effects of temperature, space velocity (LHSV) and molar ratio of the reactants on the conversion of p-cresol and products selectivities were optimized and the optimum reaction conditions evaluated were 403 K, tert-butanol/p-cresol (Bu/Cr) molar ratio 3 and LHSV 4 h−1. Under the optimized conditions, conversion of p-cresol was found to be 61 mol% with product selectivity for 2-tert-butyl-p-cresol (TBC) 81.4%, 2,6-di-tert-butyl-p-cresol (DTBC) 18.1% and tert-butyl-p-tolyl ether (ether) 0.5%. Study of time on stream (TOS) performed as a function of time for 100 h showed that the loss in activity in terms of conversion of p-cresol was 6%.