Aqueous and Template-Free Synthesis of Meso–Macroporous Polymers for Highly Selective Capture and Conversion of Carbon Dioxide

Meso–macroporous polymers possessing nitrogen functionality were innovatively synthesized through an aqueous and template-free route herein. Specifically, the polymerization of 1-(4-vinylbenzyl)-1,3,5,7-tetraazaadamantan-1-ium chloride in aqueous solution under high temperatures induces the decomposition of the hexamethylenetetramine unit into ammonia and formaldehyde molecules, followed by the cross-linking of benzene rings through “resol chemistry”. During this process, extended meso–macroporous frameworks were constructed, and active nitrogen species were incorporated. Taking the advantage of the meso–macroporosity and nitrogen functionality, the synthesized polymers offer competitive CO₂ capacities (0.37–1.58 mmol g⁻¹ at 0 °C and 0.15 bar) and outstanding CO₂/N₂ selectivities (155–324 at 0 °C). Furthermore, after complexed with metal ions, the synthesized polymers show excellent activity for catalyzing the cycloaddition of propylene oxide with CO₂ (yield>98.5 %, turnover frequency: 612.9–761.1 h⁻¹).