Sol-gel synthesis of barium hexaferrite and their catalytic application in methyl ester synthesis

Fine barium hexaferrite, BaFe12O19 has been synthesized through sol-gel technique using barium chloride dihydrate (BaCl2 center dot 2H(2)O) and iron (III) chloride hexahydrate (FeCl3 center dot 6H(2)O) as starting materials. The BaFe12O19 particles were characterized by X-ray diffraction (XRD), TGA, Fourier-Transform Infrared Spectroscopy (FTIR) and N-2 Adsorption-Desorption Isotherm. XRD revealed that high calcination temperature is beneficial for the formation of fine BaFe12O19. The results show that the crystallite size of the produced samples increased with an increase in calcination temperature. It was found that the crystalline BaFe12O19 phase was well formed above 700 degrees C. BaFe12O19 was as employed as a new heterogeneous acid catalyst for the application production of methyl ester. The suitability of BaFe12O19 as catalyst for esterification of palmitic acid was evaluated on the basis of catalyst dosage, reaction time and molar ratio of the reactants to optimize the reaction condition. The catalyst gave excellent methyl ester yield of 91.7% at optimum conditions. The optimum esterification conditions for of 0.5 g palmitic acid are; 2 wt.% of BaFe12O19 with 1: 15 molar ratio of palmitic acid to methanol at reaction temperature 120 degrees C for 2 hours.