Synthesis and optimization of 3D porous polymers for efficient CO2 capture and H2 storage

• A new Triptycene-bipyridine porous polymer (KFUPM-CO 2 ) has been synthesized and characterized. • KFUPM-CO 2 demonstrated a remarkable CO 2 uptake of 5.6 mmol/g at 273 K. • KFUPM-CO 2 displayed excellent CO 2 /N 2 selectivity (IAST selectivity of 127 at 273 K and 97 at 298 K) under simulated flue gas conditions. • KFUPM-CO 2 also exhibited 1.5 wt.% H 2 storage capacity. In this study, a new porous organic polymer (KFUPM-CO 2 ) with intrinsic nitrogen atoms as active sites for CO 2 capture was optimized and synthesized via Friedel-Crafts alkylation of triptycene and 2,2-bipyridine. The porous polymer shows a high surface area of 1100 m 2 /g with a tuned microporosity of less than 1.2 nm, confirmed by NLDFT. KFUPM-CO 2 showed a remarkable CO 2 sorption capacity of 5.6 mmol/g at 273 K, 3.2 mmol/g at 298 K, and a pressure of 760 mmHg KFUPM-CO 2 showed a high enthalpy of adsorption of 43.7 kJ/mol for CO 2 with IAST selectivity of CO 2 /N 2 of 127 at 273 K and 97 at 298 K on simulated flue gas composition. Additionally, KFUPM-CO 2 exhibited an H 2 storage capacity of 1.5 wt. % at 77 K and 860 mmHg Grand Canonical Monte Carlo (GCMC) simulations further revealed that KFUPM-CO 2 was mainly stabilized by π-π intra-molecular interactions, and exhibited strong van der Waals attractions to CO 2 molecules via the pyridyl nitrogen atoms, resulting in the rapid uptake. The combined advantages of binding 2,2-bipyridine with triptycene provided a robust porous polymer with abundant nitrogen sites, permanent porosity, and thermal stability, rendering KFUPM-CO 2 an excellent candidate for CO 2 capture and H 2 storage technologies.