Enhancing MgO efficiency in CO 2 capture: engineered MgO/Mg(OH) 2 composites with Cl - , SO 4 2- , and PO 4 3- additives.

The formation of a MgCO 3 shell hampers CO 2 capture efficiency in MgO. Our previous studies developed MgO/Mg(OH) 2 composites to facilitate CO 2 diffusion, improving capture efficiency. However, MgCO 3 still formed along the interfaces. To tackle this issue, we engineered the MgO/Mg(OH) 2 interfaces by incorporating Cl - , SO 4 2- , and PO 4 3- additives. Novel MgO-H 2 O-MgX (X = Cl - , SO 4 2- , and PO 4 3- ) composites were synthesized to explore the role of additives in preventing MgCO 3 formation. MgO-Mg(OH) 2 -MgCl 2 nano-composites displayed enhanced CO 2 adsorption and stability. This breakthrough paves the way for effective bio-inspired strategies in overcoming CO 2 transport barriers in MgO-based adsorbents.