Environmentally friendly heterogeneous sol–gel La2O3–Al2O3 mixed oxides for transesterification reaction

Abstract

Environmentally friendly heterogeneous sol–gel La2O3–Al2O3 materials with no alkaline or alkaline-earth metals were synthesized to be used as catalysts for biodiesel production by a transesterification reaction of canola oil. The effect of the La2O3 content (0, 3, 5, 7, and 10 wt%) on the catalytic performance of the La2O3–Al2O3 mixed oxides, as well as the textural, structural, and surface properties, is reported. It was found that La2O3 loading increases the number and strength of basic sites up to 7% La2O3–Al2O3 catalyst with an La2O3 monolayer formation with 0.23 mmol highly dispersed La atoms over Al2O3 is reported. A correlation between catalytic performance, informed as biodiesel production with basicity, carbonation degree, and La2O3 dispersion is obtained. The extent of biodiesel production (45% at 65 °C and 5 h of reaction time), under mild reactions conditions, for the monolayer La2O3 alumina catalyst is the highest reported up now for nontoxic heterogeneous catalysts.