Daftar Isi: Hydrolysis of Aliphatic Esters In Presence of Mixed-oxide Catalysts

Daftar Isi:

Department of Chemistry, Central College, Bangalore University, Bangalore-1 Manuscript received 16 August 1972; revised 4 .January 1973; accepted 17 February 1973 Hydrolysis of methylacetate and ethylacetate catalysed by SiO2-Al2O3, SiO2-ZrO2, SiO2-TiO2, Al2O3-ZrO2, TiO2-ZrO2 and Al2O3-TiO2 mixed-oxides have been studied and found to be reactions of the first order with respect to ester concentrations. The rate constant K for the hydrolysis of methyl acetate is greater than that for ethylacetate. The values of K decrease as the acidity of the catalyst decreases. The energy of activation for the hydrolysis of methylacetate is lower than that for the hydrolysis of ethylacetate. The value of K was also obtained from the hydrolysis of these esters in the presence of HCl (0.46 moles). The acidities of the catalysts were calculated from the ratios of the rate constants and the molar strength of HCI for each of the catalyst in the case of both the esters. The agreement between the calculated and the observed values of the acidities at pKa \(_=^<\) —3.0 shows that the acid centres of pKa \(_=^<\)—3.0 alone are able to catalyse the hydrolysis of these esters.