Heterogeneous Catalyst For Esterification Research Articles

Novel fabrication of cellulose sprinkled crystalline nanocomposites using economical fibrous sources: High performance, compatible catalytic and electrochemical properties

We report an innovative green synthesis of cellulose based copper oxide nanomaterials by simple sol-gel derived solvo-thermal method. The physio-chemical properties of nanocomposite has enhanced by dissolving filter paper, cotton (Gossypium) and kapok cotton (Ceiba pendantra) as natural cellulose materials in cuprammonium hydroxide (Schweizer's reagent). Hybrid of polysaccharide-copper oxide nanocomposite has exhibited versatility. The composites were characterized by XRD, FESEM-EDAX, HRTEM, FT-IR, UV–Vis, CV, GCD and EIS studies. The sharp XRD peaks have confirmed the crystalline monoclinic phase of CuO as well as crystalline cellulosic materials with crystalline size of 55.7 nm. The observed FT-IR peaks at 523.19 and 1118 cm−1 has proved the Cu–O stretching as well as C–O linkage in cellulose material respectively. The UV–Vis study of nanocomposites has confirmed the specific absorption property of synthesized nanomaterials. The redox peaks in CV and GCD curve have confirmed that the synthesized nanocomposites are the very good energy storage material with the specific capacitance value of 120 F g-1 at the current density of 1 A g-1. They have showed an effective antimicrobial activity against gram positive as well as gram negative bacterial strains and also exhibited good catalytic activity as heterogeneous catalyst in esterification of biodiesel production for industrial applications.

Assessment of niobium phosphate as heterogeneous catalyst in esterification with methyl acetate

AbstractBACKGROUNDThe aim of this work was to investigate the esterification reaction from oleic acid with methyl acetate (MeA) catalyzed by niobium phosphate to produce methyl esters. This catalyst has an amorphous structure and large surface area. Catalytic tests were performed according to an experimental design. The results were analyzed statistically and all of the variables were significant, especially the temperature.RESULTSA kinetic study of the reaction was carried out and the most suitable reaction conditions were 240 °C, 10% (m/m) of catalyst and MeA: oleic acid molar ratio 10:1. After 2 h, it was possible to obtain ≈80% (m/m) methyl oleate content. A noncatalytic test corroborated niobium phosphate activity in the reaction. A kinetic model fitted experimental data for the catalyzed and noncatalyzed reactions; kinetics parameters for Arrhenius equation were estimated. In a reuse test, the catalyst showed a gradual decrease in catalytic activity over five reaction cycles.CONCLUSIONNiobium phosphate can be considered as a promising heterogeneous catalyst for biodiesel synthesis. © 2019 Society of Chemical Industry

Alumina-supported Cu(II), Co(II), and Fe(II) complexes as catalyst for esterification of biomass-derived levulinic acid with trimethylolpropane (TMP) and pentaerythritol (PE) and upgrading via hydrogenation

A polyol-based ester was synthesized from biomass-derived bio-oil for application as a biolubricant. The bio-ester is biodegradable, non-toxic, and does not require mineral oil usage. Levulinic acid (LA), a major component obtained from bio-oil, was used for the catalytic esterification with two types of polyols, i.e., trimethylolpropane (TMP) and pentaerythritol (PE), in the presence of alumina-supported Cu(II), Co(II), and Fe(II) complexes as catalysts. Alumina-supported Cu(II), Co(II), and Fe(II) complexes [Cu(Tyr)(GA)]Cl-alumina, [Co(Tyr)(Amp)]Cl-alumina, and [Fe(Tyr)(Amp)]Cl-alumina were synthesized by the reaction of ligands [L-tyrosine (Tyr), Gallic acid (GA), and 2-aminopyridine (Amp)] with metal chloride salts. The catalysts were characterized by elemental analyses (CHN), magnetic susceptibility, Fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analysis/differential thermal analysis (TGA/DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) techniques. Catalytic performances of the synthesized complexes were investigated via esterification of levulinic acid with trimethylolpropane and pentaerythritol. In addition, the two best catalysts, [Cu(Tyr)(GA)]Cl and [Co(Tyr)(Amp)]Cl-alumina, were further employed for the in situ hydrogenation of levulinate esters at 120 °C to 130 °C and 7 bar to 8 bar H2 pressure for upgrading in a specially designed reactor. The alumina-supported catalysts were active, reusable, and exhibited their efficiency as heterogeneous catalysts for esterification and hydrogenation reactions for synthesizing ester-based oils.

Synthesis, Characterization and Catalytic Performance of a Novel Picolinic Acid-12-Molybdophosphoric Acid Hybrid Catalyst

A novel 12-molybdophosphoric acid (HPM)-based complex (H2PI)2(H3O)[PMo12O40][Mo2O5(H2O)2(PI)2]·11H2O (PI-HPM) was prepared by modification with picolinic acid (HPI) and characterized by the methods of Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG), X-ray powder and single crystal diffraction. The complex retained the classical Keggin structure of bulk HPM, there were some strong hydrogen bonds existing between the [PMo12O40]3- polyanion, the [Mo2O5(H2O)2(PI)2] coordination moiety, the protonated HPI and the lattice water molecules. Then PI-HPM was employed as heterogeneous catalyst for esterification reaction to evaluate its acid-catalytic activity. The complex exhibited high activity and good durability in reaction mixtures, indicating that it was a promising heterogeneous acid catalyst for esterification that including the conversion of oleic acid to oleates.

A Brønsted–Lewis-surfactant-combined heteropolyacid as an environmental benign catalyst for esterification reaction

Abstract A Bronsted–Lewis-surfactant-combined heteropolyacid (HPA) catalyst (C 16 TA)H 4 TiPW 11 O 40 (C 16 TA = cetyltrimethyl ammonium) had been designed and used as a water-tolerantly heterogeneous catalyst in esterification of free fatty acid with a higher conversion (94.7%) and excellent efficiency (91.8% yield) due to its acidic properties and structures. This micellar polyoxometalate catalyst was stable during the reaction and can be recycled by a simple separation process.

Synthesis of immobilized Brønsted acidic ionic liquid on silica gel as heterogeneous catalyst for esterification

Abstract The Bronsted acidic ionic liquid 1-(propyl-3-sulfonate) vinylimidazolium hydrogen sulfate ([(CH2)3SO3HVIm]HSO4) was immobilized on the silica gel using tetraethoxysilane (TEOS) as silica source. The properties of samples were characterized by FT-IR, elemental analysis and TG. The results showed that [(CH2)3SO3HVIm]HSO4 had been successfully immobilized onto the silica gel, and the immobilized ionic liquid catalyst (IL/silica gel) had good thermal stability. Moreover, the IL/silica gel exhibited high catalytic activity for a series of esterification and could be separated from the reaction mixture easily. It also remained satisfactory catalytic activity for the synthesis of n-Butyl acetate after 7 times recycling.