Metal organic frameworks in ionic liquid composites allow efficient CO2 capture

The chemical absorption and the physical adsorption constitute primary mechanisms in conventional CO 2 capture methods. This work proposes a novel porous ionic liquid synthesized by coupling these two mechanisms to enhance the CO 2 capture performance. Specifically, [TEPA][N-MIm] reacts with CO 2 to form carbamate species, while ZIF-8 nanoparticles are incorporated to construct stable cavity structures within the solution, providing physical adsorption sites for CO 2 . Based on CO 2 capture experiments and bubble dynamics high-speed photography experiments, CO 2 capture processes by [TEPA][N-MIm] consist of three phases: the rapid reaction phase, the slow capture phase, and the stabilization phase. Generally, improving the CO 2 mass transfer performance through methods such as increasing flowrate also enhances the capture performance. However, temperature elevation introduces more complex effects: The chemical reaction rate and the physical solubility exhibit opposing trends, and the CO 2 capture performance varies among different types of PILs. Additionally, when the solution temperature reaches a specific threshold, partial carbamate begins to decompose, leading to the stabilization of the CO 2 capture capacity.