Low-pressure CO2 fixation with epoxides via a new modified nano crystalline NH2-MIL-101(Cr) in Solvent-free and cocatalyst free condition

Abstract

Incorporation of appropriate Lewis acid centers such as Cr3+ and nucleophilic ionic species such as Br- as assistants in the opening of epoxy rings, on the metal-organic frameworks can be considered an efficient catalyst in a CO2 fixation processes. In this research work, we introduce a new catalyst by modifying the metal-organic framework and creating the ammonium salt with bromide, TEAB-MIL-101(Cr). The catalyst was characterized using several appropriate techniques and used as catalyst in the CO2 fixation reaction of a large number of epoxides. The catalytic reaction was pushed forward under solvent and cocatalyst-free conditions at 1.5 bar of CO2. The catalyst showed high activity in the presence of most epoxides, but the best result was related to epichlorohydrin, which showed 99 % conversion and 96 % selectivity to the respective cyclic carbonate within 3 h. The prepared catalyst was easily recovered and reused to the catalytic process for at least fifth times without any noticeable change in activity.