SiW₁₂O₄₀-Based Ionic Liquid Catalysts: Catalytic Esterification of Oleic Acid for Biodiesel Production

Abstract

Heteropoly acid (SiW12O40)-based ionic liquid (SWIL) and silica supported SiW12O40-based ionic liquid (SWIL/SiO2) catalysts with different contents of SWIL were designed and prepared. The structures of the catalysts were experimentally characterized and theoretically analyzed, and catalytic activities and reusability of the catalysts were evaluated through an esterification reaction between oleic acid and methanol. The results showed that SWIL had excellent activity and good reusability. SWIL dissolved in the reaction mixture during the reaction process and could be precipitated and separated from products at room temperature after methanol and water were removed. The fresh SWIL/SiO2 had high catalytic activity close to that of SWIL and could be easily separated from the reaction system just through simple filtration. However, the leaching of SWIL in the esterification reaction caused the deactivation of SWIL/SiO2. SWIL contents of SWIL/SiO2 played an important role on the catalytic activity and reusability of SWIL/SiO2.

Encapsulation of Heteropolyanion‐Based Ionic Liquid within the Metal–Organic Framework MIL‐100(Fe) for Biodiesel Production

“…The [SO 3 H-(CH 2 ) 3 -HIM] [HSO 4 ]@MIL-100 catalyst prepared through the direct impregnation of MIL-100 with the ionic liquid also demonstrated high activity, but its reusability was low (Figure 7). The [SO 3 H-(CH 2 ) 3 -HIM] 3 PW 12 O 40 @MIL-100 catalyst demonstrated desirable activity compared with other catalysts, [49][50][51][52][53] which indicated that the prepared catalyst had a high catalytic activity for the esterification of oleic acid.…”

HPAs and POM‐based ILs Catalyzed Effective Conversion of Furfuryl Alcohol to Alkyl Levulinate

“…Eight characteristic signals at δ =8.7, 7.5, 7.4, 4.3‐4.2, 3.9, 2.9‐2.8, 2.0‐1.9 and 1.8‐1.7 in the 1 H NMR spectra and signals at δ =136, 123, 122, 50, 49, 35, 28 and 21 in the 13 C NMR spectra were observed for all four POM‐based ILs, [MIMBS] 3 [PW 12 O 40 ] (Figure S6), [MIMBS] 4 [SiW 12 O 40 ] (Figure S8), [MIMBS] 5 [BW 12 O 40 ] (Figure S10) and [MIMBS] 5 [AlW 12 O 40 ] (Figure S12), which are slightly different from the NMR data obtained for 4‐(1‐Methylimidazolium‐3‐yl)butane‐1‐sulfonate (Figure S3, 1 H NMR δ=8.8, 7.6, 7.5, 4.4‐4.3, 4.0, 3.0‐2.9, 2.1‐2.0, 1.8‐1.7, and Figure S4, 13 C NMR δ=136, 124, 122, 50, 49, 36, 28, 21). These results indicated the presence of interation between HPA anion and 4‐(1‐methylimidazolium‐3‐yl)butane‐1‐sulfonate cation in POM‐based ILs, not simple physically mixed.…”

Ionic liquids and supercritical carbon dioxide: green and alternative reaction media for chemical processes

“…The heterogeneous system was also studied. Zhen et al (2012) reported the design and preparation of a heteropoly acid (SiW 12 O 40 )-based IL (SWIL) and silica supported (SWIL/SiO 2 ) catalysts with different contents of SWIL. The structures of the catalysts were experimentally characterized and theoretically analyzed, and catalytic activities and reusability of the catalysts were evaluated through the esterification of oleic acid with methanol.…”