Synthesis, characterization and reactivity of Lewis acid/surfactant cerium trisdodecylsulfate catalyst for transesterification and esterification reactions

• Published in: Applied catalysis. A, General General, 2009-02, Vol.355 (1), p.139-147
• Main Authors: Ghesti, Grace Ferreira, Macedo, Julio Lemos de, Parente, Vicente Cavalcanti Ibiapina, Dias, José Alves, Dias, Sílvia Cláudia Loureiro
• Format: Article
• Language: English
• Subjects: Biodiesel; Catalysis; Cerium trisdodecylsulfate; Chemistry; Esterification; Exact sciences and technology; General and physical chemistry; Lewis acid-surfactant-combined catalyst; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Transesterification
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2008.12.008

The Lewis acid/surfactant cerium trisdodecylsulfate catalyst was prepared, characterized, and applied in the production of alkyl esters by solvent-free transesterification and esterification reactions. High catalytic activities were found for the reaction of soybean oil and oleic acid with light alcohols. The recovered catalyst was recycled without loss of catalytic activity. This article reports the synthesis, characterization and application of cerium(III) trisdodecylsulfate trihydrate (Ce[OSO 3C 12H 25] 3·3H 2O) as a Lewis acid-surfactant-combined catalyst for the production of alkyl esters by solvent-free transesterification and esterification reactions. The new material presents a bilayer lamellar arrangement with an interplanar spacing of d 001 = 3.76 nm, and the dodecylsulfate headgroup in a C 2v symmetry. The reaction of soybean oil and oleic acid with light alcohols (methanol and ethanol) was used as model reactions and high catalytic activity (TOF = 57.4 mol h −1 mol cat −1) was observed. The catalyst converted the used feedstocks to esters in less than 4 h with yields greater than 95%. In addition, it can be used to produce biofuels from unrefined and waste oils in which both triacylglyceride and free fatty acid molecules are present. After reaction, the recovered catalyst maintained its activity (≥95%) for three cycles. The catalyst was characterized by elemental analysis, X-ray powder diffraction (XRD), thermal analysis (thermogravimetry (TG)/derivative thermogravimetry (DTG)/differential thermal analysis (DTA)), pyridine adsorption, and spectroscopic analysis (FTIR and NMR).