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.