Enhancing MgO efficiency in CO2 capture: engineered MgO/Mg(OH)2 composites with Cl−, SO42−, and PO43− additives

Abstract

The formation of a MgCO₃ shell hampers CO₂ capture efficiency in MgO. Our previous studies developed MgO/Mg(OH)₂ composites to facilitate CO₂ diffusion, improving capture efficiency. However, MgCO₃ still formed along the interfaces. To tackle this issue, we engineered the MgO/Mg(OH)₂ interfaces by incorporating Cl⁻, SO₄²⁻, and PO₄³⁻ additives. Novel MgO–H₂O–MgX (X = Cl⁻, SO₄²⁻, and PO₄³⁻) composites were synthesized to explore the role of additives in preventing MgCO₃ formation. MgO–Mg(OH)₂–MgCl₂ nano-composites displayed enhanced CO₂ adsorption and stability. This breakthrough paves the way for effective bio-inspired strategies in overcoming CO₂ transport barriers in MgO-based adsorbents.