High-temperature synthesis of strong acidic ionic liquids functionalized, ordered and stable mesoporous polymers with excellent catalytic activities

Abstract

Strong acidic ionic liquids functionalized, ordered and stable mesoporous phenol-formaldehyde resins (OMR-ILs) monoliths have been successfully synthesized from the treatment of ordered mesoporous resins (OMR-[HMTA]) using 1,3-propanesultone, followed by ion exchanged using various strong acids. The OMR-[HMTA] samples could be synthesized by the assembly of block copolymer template of F127 with preformed resol, which could be obtained from heating a mixture of phenol and formaldehyde at 70 °C; during curing processes, certain contents of the hexamethyltetramine (HMTA) cross linker were also introduced, after hydrothermal treatment at 200 °C for 20 h, calcination at 360 °C under nitrogen, OMR-[HMTA] samples with opened mesopores were obtained. Characterizations suggest that OMR-ILs have ordered and stable mesospores, high BET surface areas, and strong acid strength. Interestingly, OMR-ILs show much higher catalytic activities and recyclability in the esterification of acetic acid with cyclohexanol, hydration of propylene oxide, Peckmann reaction of resorcinol with ethyl acetoacetate and transesterification of tripalmitin with methanol than those of Amberlyst 15, sulfonic group functional ordered mesoporous silicas and acidic zeolites, which were even comparable with that of H 2 SO 4 . The unique features of OMR-ILs such as superior thermal stability, excellent catalytic activities and recyclability, will be potentially important for their applications in industry. † Electronic supplementary information (ESI) available. See

A hierarchical meso-macroporous poly(ionic liquid) monolith derived from a single soft template

“…), 1,2 providing numerous new functionalities that can be applied in the fields of adsorption, separation, catalysis and so on. [3][4][5][6][7] The practical performances of MPILs are closely related to their pore structures, which motivates the development of various pore formation strategies. [8][9][10][11][12] However, MPILs are synthesized through a self-assembly process 9,10 (except the one example of a hard-templating route 11 ), and have never been achieved through a soft-templating pathway.…”

Meso‐macroporous Carbons Decorated with Ample Nitrogen Sites as Bifunctional Catalysts in CO2 Catalytic Conversion and Oxygen Reduction Reaction

“…The structural characteristics of 3D‐NHPC‐x were determined by low‐temperature N 2 adsorption. As displayed in Figure 2, all samples show type‐IV isotherms with large adsorption amount at higher relative pressure range of 0.88∼1.0, which indicates the ample presence of meso‐macroporous structures in those of samples [38–46] . Moreover, wide distribution ranging from 0 to 50 nm was found all the 3D‐NHPC‐x samples, confirming the formation of hierarchical nanopores in 3D‐NHPC‐x [47–55] .…”

Ordered Mesoporous Polymers for Biomass Conversions and Cross‐Coupling Reactions

“…Compared to various reported porous organic polymers—crystalline covalent organic frameworks, porous aromatic frameworks with amorphous networks, conjugated microporous polymers, and mesoporous polydivinylbenzene—OMPs possess unique characteristics such as tunable periodic structures, ordered and uniform mesopores, and adjustable mesopore sizes (2–30 nm) . These characteristics make the active sites anchored on the OMP network more readily accessible to various substrates, which is favorable for enhancing their activities to catalyze the transformation of various low‐cost substrates such as biomass into fine chemicals and biofuels . In addition, OMPs can be used as a facile cost‐effective approach for the synthesis of highly ordered mesoporous carbons (OMCs) through a direct carbonization processes, which act as a bridge connecting OMPs and OMCs.…”

“…Various catalytically active heteroatoms, such as nitrogen and sulfur, can be introduced into their networks by introducing heteroatom‐containing precursors or by post‐treatment during the synthetic processes. This partially sacrifices the ordering of mesopores in the OMPs, resulting in limited concentrations and poor dispersion of catalytically active sites …”