Imidazolium-based titanosilicate nanospheres as active catalysts in carbon dioxide conversion: Towards a cascade reaction from alkenes to cyclic carbonates

Imidazolium-Containing Hybrid Organic–Inorganic Materials for the Conversion of CO2: Unveiling the Key Role of the Ionic Template

“…Mesoporous silica-based materials were prepared adapting a previously reported method. , Ammonia (10.95 mmol) and CTAB (1.516 g, 4.16 mmol) were dissolved in 725 mL of distilled water. When a clear solution was obtained, TEOS (6.936 g, 33.29 mmol) was added dropwise to the aqueous solution.…”

“…18 A third series of materials was prepared via grafting on the surface of a silica-based material XS-MCM-41 the Nmethylimidazolium salts as already reported by our group. 3,5 All of the materials were fully characterized. The regular porosity of the HOIM was assessed by low-angle X-ray diffraction (XRD) and N 2 -physisorption, while the insertion of the Si-imi-Si in the silica structure was evaluated by 29 Si and 13 C MAS NMR, X-ray photoelectron spectroscopy (XPS), and combustion chemical analysis.…”

“…This strategy usually requires the synthesis of a material that is postfunctionalized on the surface. The postfunctionalization by an imidazolium salt, for instance, can be performed through the functionalization of the surface by a linker (e.g., chloropropyl or bromopropyl moieties) followed by its nucleophilic substitution by an imidazole derivative to generate the corresponding imidazolium salt. − The generation of various imidazolium-containing materials by cosynthesis was reported too. Some solid catalysts were synthesized starting from a homogeneous imidazolium salt which is polymerized, , either via the vinyl extremities − or through poly nucleophilic substitution. − The modification of terephthalic acid by imidazolium was also a strategy recently developed to obtain an imidazolium-functionalized metal–organic framework (MOF). − MOFs present the advantage over polymers of possessing a high specific surface, due to their elevated degree of organization.…”

“…For the sake of comparison, a second series of materials was prepared using CTAB as SDA which should suffer from the S + I + repulsion (Scheme ; right) . A third series of materials was prepared via grafting on the surface of a silica-based material XS-MCM-41 the N -methylimidazolium salts as already reported by our group. , …”

“…The data are in agreement with the ones reported for materials prepared under similar conditions and already reported by our group. 4,5 An additional material with a higher Si-imi-Si/TEOS ratio (25/75 instead of 10/90 mol %) was also attempted. The material was washed under a Soxhlet with EtOH acidified with HBr.…”