Synthesis of metal-phenanthroline-modified hypercrosslinked polymer for enhanced CO₂ capture and conversion via chemical and photocatalytic methods under ambient conditions

Catalytic conversion of CO2 into valuable chemicals is a promising approach to mitigate the greenhouse effect and alleviate energy shortages. Hypercrosslinked polymers (HCPs) offer a scalable and stable platform for this conversion, but they often suffer from low CO2 adsorption and activation capabilities, necessitating high temperatures and pressures for effectiveness. To overcome these limitations, nitrogen-based CO2-philic active sites have been integrated into the structure of HCPs, enhancing CO2 attraction and leading to superior adsorption performance. The incorporation of cobalt ions further bolsters CO2 affinity, with HCP-PNTL-Co-B achieving the highest observed adsorption heat of 33.0 kJ·mol-1 alongside a substantial 2.0 mmol·g-1 CO2 uptake. These modified HCPs exhibit higher yields and reaction rates in cycloaddition reactions with cocatalyst tetrabutylammonium bromide at room temperature and atmospheric pressure, while HCP-1,10-phenanthroline (PNTL)-Co-B demonstrates a higher CO production rate (2,173 μmol·g-1·h-1) and selectivity (84%) in photocatalytic reduction reaction. This research has successfully achieved outstanding carbon dioxide capture and conversion performance at room temperature and atmospheric pressure by introducing CO2-philic active sites and cobalt ions into HCPs via facile one-step polymerization. This study provides a new method to design highly efficient organic catalysts for CO2 conversion.