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

Abstract

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 ).