Lanthanum oxide behavior in La2O3-Al2O3 and La2O3-ZrO2 catalysts with application in FAME production

Abstract La 2 O 3 monolayer catalysts with 90% coverage on Al 2 O 3 and 71% on ZrO 2 were successfully obtained by a sol–gel method and the catalytic performance evaluated as fatty acid methyl esters (FAME) production in a canola oil transesterification reaction show differences upon the nature and extent of basic sites. The La 2 O 3 monolayer does not modify strongly the textural properties of the Al 2 O 3 and larger structural changes are detected on ZrO 2 . For the La 2 O 3 -Al 2 O 3 monolayer catalyst, the inter-diffusion Al 3+ /La 3+ cation modify the nature of the acidity and increases the basicity of the Al-O-La species, whereas for the La 2 O 3 -ZrO 2 monolayer catalyst, appearance of tetragonal ZrO 2 structure with larger basicity is detected. The effect of the nature of the support in the catalytic performance in FAME production of the La 2 O 3 -ZrO 2 and La 2 O 3 -Al 2 O 3 monolayer catalyst informed as FAME % (60% at 5 h and 65 °C) for the La 2 O 3 -ZrO 2 is attributed to the presence of the new medium strength basic sites and the m-ZrO 2 structure, whereas the lower basicity of the La 2 O 3 -Al 2 O 3 explain the lower fatty acid methyl esters production (45% at 5 h and 65 °C).