Fatty acid methyl ester synthesis catalyzed by solid superacid catalyst SO42-/ZrO2–TiO2/La3+

A new type of solid superacid catalyst with the composition of SO42-/ZrO2–TiO2 loaded with lanthanum was prepared by precipitation and impregnation. The catalytic performance for the synthesis of fatty acid methyl ester from fatty acid and methanol was investigated. The influences of preparation conditions on catalyst performance were studied, the optimum results of which showed that amount of La(NO3)3 was 0.1 wt.%, the concentration of H2SO4 for impregnation was 0.5 mol l−1 and calcination temperature was 550 °C. In addition, the effects of reaction parameters on esterification efficiency were also studied. With the catalyst amount of 5 wt.%, methanol amount of 1 ml/g fatty acid (FA) and reaction duration of 5 h at 60 °C, the conversion ratio could reach above 95%. The catalyst recycled without any treatments could exhibit high activity with the conversion efficiency of above 90% after being reused five times.