A novel supported ionic liquid membrane reactor for catalytic CO2 conversion

Converting CO2 into cyclic carbonates is one of the most promising ways to help mitigate global climate change. In this paper, we developed a novel supported ionic liquid membrane (SILM) that integrates reaction and gas permeation functions into a single unit for efficient synthesis of propylene carbonate (PC) under solvent-free, cocatalyst-free, and catalyst-free separation conditions. The catalytic stability of SILM was verified by batch experiments, and the structure, morphology and composition were characterized by XRD, SEM, and EDS. Also, the process parameters of continuous membrane catalysis were evaluated for PO conversion, PC selectivity, space-time yield and PO flux. By comparative analysis, polyvinylpyrrolidone (PVP) could not only effectively inhibit the loss of ionic liquid (IL), but also help to form a stable membrane layer. Characterization results confirmed that IL was basically concentrated in the top layer of γ-Al2O3 rather than the intermediate layer. Besides, the essential factors were identified to provide a feasible route for the large-scale conversion of CO2.