Heteroatom driven activation and conversion of CO2 using cyclophosphazene based inorganic-organic hybrid nanoporous materials

Inexpensive and nontoxic metal-free heteroatom (P, N, and O) enriched high surface area nanoporous materials (CHNM and HNM) as efficient heterogeneous catalysts for the conversion of epoxides to cyclic carbonates by utilizing CO2 is reported. The catalysts were made by condensing the heteroatom enriched precursor with melamine and pyrrole to produce HNM and CHNM, respectively. The catalysis was carried out under mild experimental conditions, i.e. 100 degrees C reaction temperature and 4 bar CO2 pressure under solvent-free conditions. Almost 100% conversion can be realized using HNM as a catalyst and this superior performance was attributed to the presence of larger heteroatoms as compared to CHNM, although the latter has 159% specific surface area and 115% pore volume as compared to the former. The obtained results are discussed in terms of the Lewis acid-Lewis base interaction, textural properties and the frameworks of the catalysts and the reactants.

Automated summary

In this study, inexpensive and nontoxic metal-free heteroatom enriched nanoporous materials were used as efficient catalysts for the conversion of epoxides to cyclic carbonates utilizing CO2. The catalysts, HNM and CHNM, were synthesized by condensing heteroatom enriched precursors with melamine and pyrrole. Under mild experimental conditions, almost 100% conversion was achieved using HNM as a catalyst, attributed to the presence of larger heteroatoms compared to CHNM despite its higher specific surface area and pore volume. Discussions were made on Lewis acid-Lewis base interaction, textural properties, and frameworks of the catalysts and reactants in relation to the obtained results.