resumo
Covalently supported ionic liquids in mesoporous materials were prepared by grafting 1-methyl-3-(3-trimethoxysylilpropyl)imidazolium chloride in MCM-41. Subsequently, the [Cl-] anion was changed to [BF4-], [PF6-] or [Tf2N-]. These materials that present an advantageous combination of the properties of mesoporous solid materials and ionic liquids were evaluated for CO2 sorption as well as catalysts for CO2 conversion into cyclic carbonate using propylene oxide. The material with the [Cl-] anion had the best performance for both CO2 sorption and conversion. A CO2 sorption of 11 w/w% on the adsorbent was achieved and the cycloaddition reaction exhibited a conversion of 67% with 82% selectivity with the catalyst remaining active after 5 cycles, proving that the same sorbent/catalyst setup can be used for both CO2 capture and conversion. Based on the experimental data and electronic-structure numerical simulations, we have hypothesized two major reasons why chloride out performs other anions when adsorbed on MCM-41 unlike unsupported ionic liquids.
palavras-chave
MAGNETIC SUSPENSION BALANCE; CARBON-DIOXIDE SOLUBILITY; CYCLIC CARBONATES; MCM-41; ADSORPTION; CATALYST; CYCLOADDITION; EPOXIDES; MATRIX; TRANSFORMATION
categoria
Chemistry
autores
Aquino, AS; Bernard, FL; Borges, JV; Mafra, L; Dalla Vecchia, F; Vieira, MO; Ligabue, R; Seferin, M; Chaban, VV; Cabrita, EJ; Einloft, S
nossos autores
Luís Mafra
Investigador Principalagradecimentos
AA thanks CAPES (process no. 9259120) and JB thanks CNPq (PIBIC 3475) for scholarships and SE and RL thanks CNPq for DT scholarship. V. V. C. acknowledges research grant from CAPES under the