Metallo-tetraphenylporphyrin-Based Porous Organic Polymers: Effect of Metal Components on Carbon Dioxide Adsorption and Conversion

A series of metalated porous organic polymers (POPs) derived from tetraphenylporphyrin (TPP) was synthesized, and the specific surface areas, selectivities for CO₂ over N₂, and conversion properties of the POPs were investigated. The metallo-tetraphenylporphyrin-based porous organic polymers were characterized using FT-IR, ¹³C-NMR, TGA, XRD, XPS, HR-FESEM, and EDX. Among the five catalysts studied, non-metalated TPP-based POP exhibited the highest BET surface area of 524.04 m²g⁻¹, whereas the Ni(II)TPP-based POP had the greatest CO₂/N₂ selectivity at both 298 and 323 K. In terms of the catalytic efficiency for the conversion of styrene oxide to styrene carbonate using CO₂, 2HPOP exhibited the highest yield of 91.67%, while the yield obtained with the metalated POPs was approximately 20%. This result suggests that the catalytic efficiency for CO₂ conversion is determined by both the selectivity and surface area of the metalated POPs. Moreover, the improvement in the CO₂/N₂ selectivity resulting from metalation did not play a dominant role in counterbalancing and surpassing the decrease in porosity.