Creation of Dopant Synergism in Porous Organic Diatomic Nanoscale Network for Catalytic CO₂ Conversion

Designing sustainable catalytic platforms for efficient CO2 conversion remains a significant challenge due to the thermodynamic stability and kinetic inertness of CO2. In this study, we present a series of porous organic polymers (POPs) functionalized with varying heteroatoms such as nitrogen (N-POP), sulfur (S-POP), and a combination of both (SN-POP), synthesized using cost-effective methods, including Friedel–Crafts alkylation, Suzuki coupling, and FeCl3-mediated oxidative polymerization. The SN-POP framework exhibited the highest CO2 adsorption capacity (2.2 mmol/g at 273 K) and superior catalytic efficiency in the carboxylative cyclization of propargylic alcohols, achieving 96% conversion with 100% selectivity to α-alkylidene cyclic carbonates under ambient conditions. Notably, the morphological tuning via diverse polymerization approaches resulted in distinct micro- and mesoporous architectures, influencing both the CO2-philicity and catalytic behavior. Comprehensive characterization via PXRD, FTIR, TGA, XPS, and N2 adsorption studies confirmed the porosity and stability of the materials. In-situ ATR-SEIRAS analysis played a fundamental role in identifying the surface-active sites of the catalysts, and NMR spectroscopy provided critical insight into the structure–function relationships and surface reactivity of the materials. Real-time spectroscopic investigations coupled with DFT-based simulations enabled us to decode the mechanistic pathway, revealing synergistic heteroatom interactions at the molecular level that facilitate CO2 activation and substrate cyclization. This integrated experimental–theoretical approach underscores the pivotal role of morphological design and advanced analytics in elucidating catalyst behavior and advancing the development of efficient sustainable catalytic systems for carbon fixation.