ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

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

Daniela Salinas, Catherine Sepulveda, Nestor Escalona, and Gina Pecchi

Universidad del Biobío, Concepción, Chile

E-mail: dsalinas@ubiobio.cl

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.

Keywords: La₂O₃–Al₂O₃ ; sol–gel ; Biodiesel ; Monolayer ; Basicity 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-018-0471-1

Chemical Papers 72 (9) 2353–2362 (2018)