Stable poly (ionic liquids) with unique cross‐linked mesoporous‐macroporous structure as efficient catalyst for alkylation of o‐xylene and styrene

Abstract

In this work, using divinylbenzene (D), 1-vinylimidazole (V) and 1-vinyl-3butylimidazolium bromide ([VBIM][Br]) as monomers, the binary-monomer poly (ionic liquids) (PILs) and ternary-monomer PILs were successfully synthesized, via hydrothermal polymerization and anion exchange, sequentially. Compared with each other, the ternary polymeric acidic IL catalyst has a clear spongy porous structure, while having a more stable macroporous structure, a larger specific surface area, more acidic groups and more active sites. Catalytic performance of catalyst was investigated through the alkylation of o-xylene and styrene. The effect of the amount of IL added and the length of the cation chain on the ternary polymerization of acidic IL was systematically investigated.Under optimal reaction conditions (molar ratio of monomers was D:V: [VBIM][Br] = 2:1:1, the most suitable cation chain length was C 4 ), the synthesized MPD-[C 4 V]-[VBIM][SO 3 CF 3 ] has a larger specific surface area (89.47 m 2 /g), large pore volume (0.29 cm 3 /g), and abundant mesopores and macropores, which help to improve the contact between the active site and reactants. Moreover, the catalyst could maintain a relatively high conversion of styrene (99.0%), 1,2-diphenylethane yield (98.7%) and high thermostability under reaction and be easily be divided from the solution, which is critical for heterogeneous solid catalysts.

Constructing High-Recognition Protein-Imprinted Materials Using “Specially Designed” Block Macromolecular Chains as Functional Monomers and Crosslinkers

“…Compared with SiO 2 , SiO 2 @MPS showed a characteristic peak of CO stretching vibration at 1716 cm –1 , which originated from the modification of the silane coupling agent . For SiO 2 @MPS@MIPs-MFM and SiO 2 @MPS@NIPs-MFM samples, the peaks at 1456 and 1549 cm –1 were ascribed to the deformation and stretching vibration of the imidazolium ring, indicating the successful grafting polymerization of MFM. , The surface elemental composition of SiO 2 @MPS, SiO 2 @MPS@MIPs-MFM, and SiO 2 @MPS@NIPs-MFM was further determined by XPS analysis. It can be seen from Figure B that the SiO 2 @MPS microsphere contained only Si, O, and C elements, whereas both MIPs and NIPs showed new signals at 399.6, 130.6, 255.2, 69.1, 198.7, 229.1, and 164.0 eV, which were attributed to the characteristic peaks of N 1s, P 2p, Br 3s, 3d, Cl 2p, S 2s, and 2p, respectively. ,, In addition, thermogravimetric analysis (TGA) results in Figure C also showed that SiO 2 @MPS@MIPs-MFM and SiO 2 @MPS@NIPs-MFM had higher weight loss than the bare SiO 2 @MPS microsphere in the temperature range from 100 to 600 °C, which may be caused by the decomposition of the polymer layer .…”

“…38 For SiO 2 @MPS@MIPs-MFM and SiO 2 @MPS@NIPs-MFM samples, the peaks at 1456 and 1549 cm −1 were ascribed to the deformation and stretching vibration of the imidazolium ring, indicating the successful grafting polymerization of MFM. 30,39 The surface elemental composition of SiO 2 @MPS, SiO 2 @MPS@MIPs-MFM, and SiO 2 @MPS@NIPs-MFM was further determined by XPS analysis. It can be seen from Figure 3B to the characteristic peaks of N 1s, P 2p, Br 3s, 3d, Cl 2p, S 2s, and 2p, respectively.…”

Heterogeneous Catalysis with the Participation of Ionic Liquids

“…The systems of this type were characterized by a greater number of acid groups and active centers on their surface than their binary analogs. Additionally, the presence of micro-and mesopores in the structure of the porous ternary polymer increased the possibility of contact between reagents, which resulted in the high conversion of substrates (99%) [117]. The high activity of porous ionic liquids as catalytic systems can be achieved not only by the formation of certain structures but also by the generation of acid-base properties.…”

Influence of FeCl3‐modified chloroaluminate ionic liquids on long‐chain alkenes alkylation

“…[11][12][13][14][15] Alkylation catalyzed by acidic ILs is one of the focuses of catalysis study due to the possibility of acidity control and the unique physicochemical properties. [16][17][18][19][20][21][22][23] For example, 1-alkyl-3-methylimidazolium halidealuminum chloride ILs have been investigated as catalysts for isobutane/2-butene alkylation. [24,25] Lewis acidic chloroaluminate ILs synthesized by aluminum chloride and triethylamine hydrochloride has also been confirmed to be an excellent catalyst for alkylation.…”