K2O supported on sol-gel CeO2-Al2O3 and La2O3-Al2O3 catalysts for the transesterification reaction of canola oil

Abstract Heterogeneous supported potassium on promoted CeO 2 -Al 2 O 3 and La 2 O 3 -Al 2 O 3 sol-gel mixed oxides was used as a catalyst for biodiesel production via the transesterification of canola oil with methanol using a batch reactor. These mixed oxides alone do not show any catalytic activity in the transesterification reaction, and the incorporation of potassium increases the catalytic activity, which is greater in the La 2 O 3 -promoted catalysts. The improved catalytic activity of the potassium La 2 O 3 -promoted catalysts was associated with the partial insertion of lanthanum into alumina with a favorable interaction between the potassium and the oxygenated species of the La 2 O 3 -Al 2 O 3 mixed oxide. The larger amount of K 2 O species in K 2 O/5La 2 O 3 -Al 2 O 3 and the lower acidity explain their large production of biodiesel. Moreover, the leaching resistance of potassium is remarkable, with the K 2 O/5La 2 O 3 -Al 2 O 3 catalyst showing