Tailored pores, enhanced activity: Porous organic polymer-supported metallocene catalysts for ethylene polymerization

Immobilizing metallocene catalysts on suitable carriers can overcome the drawbacks of their homogeneous counterpart in catalyzing olefin polymerization. However, the development of porous organic carriers with tunable specific surface area, pore structure and commendable compatibility for metallocene catalyst loading remains challenging. In this study, porous organic polymers (POPs) with tunable specific surface area (158–1407 m²/g) and pore volume (0.15–1.04 cm³/g) were successfully fabricated by a facile one-pot method through direct knitting of aromatic copolymer monomers. We provided a comprehensive investigation into the impact of specific surface area, pore structure and chemical structure of POPs on the catalytic polymerization of ethylene as POPs-supported metallocene catalysts. The results reveal that interactions among POPs, MAO and Cp₂ZrCl₂ govern both the formation and spatial distribution of active sites as well as the overall catalytic activity. The catalytic kinetics show that the POPs-supported metallocene catalysts exhibited no initiation period during ethylene polymerization. And the catalytic activity (20513 kgPE(mol Zr)⁻¹h⁻¹) is reached with a support possessing a specific surface area of 438 m²/g and a pore volume of 0.26 cm³/g. This work highlights the significant potential of POPs as tailor-made porous organic polymer carriers for metallocene-catalyzed ethylene polymerization.