Novel Ti and Mn Mesoporous Molecular Sieves: Synthesis, Characterization and Catalytic Activity in the Epoxidation of Vegetable Oil

Abstract

The novel mesoporous materials containing titanium and manganese, Ti-HMS (50) and Mn-HMS (50) (the number 50 denoting the Si/metal of molar ratio), were synthesized using laurylamine as template at room temperature. They were characterized by a series of techniques including powder XRD, FT-IR, UV-Vis spectroscopy, TEM, TG and Nitrogen physisorption. The results indicated that titanium and manganese had been incorporated into the HMS and both them had a wormhole mesopore structure. It also suggested that Mn 2? and Mn 3? coexisted in the Mn-HMS, Ti 4? in Ti-HMS. Besides, epoxidation of soybean oil over these synthesized catalysts was performed using tert-butyl hydroperoxide (TBHP) as oxidant. An increase in the activity was observed when surface area, pore diameter and hydrophobic nature were increased, which meant more active center reacting with soybean oil (SBO), also could reduce the energy barrier and avoid the oxirane ring opening. Furthermore, the result indicated that Mn-HMS showed a higher selectivity (up to 82.9% for Mn and 51.1% for Ti), but Ti-HMS exhibited a better conversion.

Technological Aspects of Chemoenzymatic Epoxidation of Fatty Acids, Fatty Acid Esters and Vegetable Oils: A Review

“…There are a few industrially important vegetable oil epoxidation methods: Reaction with pre-produced peroxyacids or generated in situ in acidic homogeneous medium [23,28,29,30,31,32],Epoxidation with peroxyacids in the presence of cationic ion-exchange resins (Amberlite ® IR-122, Amberlite IR 120H, KU-2 × 8) [33,34,35,36,37,38,39,40,41,42,43,44,45],Epoxidation over phosphotungstate heteropolyacid catalysts and in the presence of phase-transfer catalysts (H + /WO 4 −2 /PO 4 −3 /Q + X − ), QX-onium salt [42,43],Epoxidation over titanium-silicalite catalysts (Ti(IV)-SiO 2 , Ti-MCM-41, and amorphous Ti/SiO 2 ) [39,44,46,47],Epoxidation in the presence of transition metal complexes as catalysts (CH 3 ReO 3 or CH 3 ReO 3 /Nb) [48,49],Epoxidation in the presence of aluminium trioxide, obtained by a sol-gel method [50],Chemoenzymatic epoxidation [28,51,52,53,54,55]. …”

“…Epoxidation over titanium-silicalite catalysts (Ti(IV)-SiO 2 , Ti-MCM-41, and amorphous Ti/SiO 2 ) [39,44,46,47],…”

Epoxidation of Vegetable Oils via the Prilezhaev Reaction Method: A Review of the Transition from Batch to Continuous Processes

“…However, these catalysts gave a poor efficiency in the epoxidation of bulky molecules such as triglycerides due to diffusion limitations for their large mean molecular diameters. Other promising heterogeneous catalysts have been tested, such as metal catalysts and metal complexes, ,− commercial alumina, ,− polyoxometalates − and mesoporous molecular sieves. − Unfortunately, although good double bond conversions and epoxy selectivity have been obtained using these catalysts, most of them have strong limitations, such as separation problems and activity decline over time. Moreover, the high preparation cost, the need of a solvent to homogenize the reaction medium, and both the low selectivity and conversion in reactions with VOs compared to the conventional method are the major drawbacks of this approach.…”

Synthesis of polyols containing nitrogen‐phosphorus from vegetable oil derivatives for polyurethane film applications

“…11,12 Carboncarbon double bonds and ester groups of vegetable oils are two main functional groups used for chemical transformation. Therefore, hydroxyl group can be introduced into the structure of vegetable oil through the chemical reaction such as alcoholysis, 13 ozonation, 14 and epoxyopening method. 15 And the vegetable oil-based polyols can replace petroleum-based polyols to react with isocyanate as the raw materials for the synthesis of polyurethane.…”