Two kinds of POSS-based organic–inorganic hybrid porous materials have been synthesized via Friedel–Crafts and Scholl coupling reactions, for the first time, using low-cost building blocks i.e., octaphenylsilsesquioxanes and simple knitting approaches to obtain high Brunauer–Emmett–Teller (BET) surface area porous polyhedral oligomeric silsesquioxane (POSS)-based hybrid materials. N₂ sorption isotherms of the polymers show that both these materials are predominantly microporous and mesoporous with BET surface areas of 795 m² g⁻¹ for the polymer of octaphenylsilsesquioxanes-1 (POPS-1) and 472 m² g⁻¹ for the polymer of octaphenylsilsesquioxanes-2 (POPS-2). Moreover, POPS-1 can reversibly adsorb 9.73 wt% CO₂ (1 bar and 273 K) and 0.89 wt% H₂ (1.13 bar and 77 K), and POPS-2 shows moderate gas uptake with 8.12 wt% CO₂ (1 bar and 273 K) and 0.64 wt% H₂ (1.13 bar and 77 K). In addition, the structural integrity of POSS based building blocks was completely preserved under relatively strong acidic conditions.