Unity Makes Strength: Constructing Polymeric Catalyst for Selective Synthesis of CO2/Epoxide Copolymer

Catalyst design strategies such as bi-functional and di-nuclear catalysts have been developed based on intramolecular interactions, achieving excellent cat-alytic performance. However, most of these catalysts work in a state of disunity. To make progress in this direction, we reckoned that enhancing the neglected intermolecular interactions of these catalysts might be a suitable approach. Herein, we report a strategy of constructing homogeneous polymeric catalysts based on the philosophy of "unity makes strength" to convert the intermolecular interactions into stron-ger intramolecular interactions. We united discrete active centers of aluminum (Al) porphyrin and tertia-ry amine (methyl methacrylate; MMA) via a random copolymerization process into one polymer chain with the subsequent metallization using low-toxic metal AlEt2Cl, to construct polymeric catalysts for selective copolymerization of CO2/epoxide. The spa-tial confinement enabled the multiple interactions among the active centers, which was distinct from the "point-to-point" interacting systems such as bi-nary, bi-functional, or di-nuclear complexes. Through detailed tuning of the multiple synergistic effects between porphyrin/porphyrin (metal synergistic ef-fect) and Al porphyrin/tertiary amine (Lewis pair effect), the optimized polymeric catalyst showed significantly boosted catalytic activity of 4300 h-1, much higher than their mono-nuclear (similar to 0 h-1) and homo-polymeric (750 h-1) counterparts. Our present approach for designing polymeric catalysts based on multiple synergistic effects provides a platform for developing highly active catalysts.