Efficient synthesis of styrene carbonate from CO2 and styrene oxide using zinc catalysts immobilized on soluble imidazolium–styrene copolymers

Preparation of zinc catalysts (Zn/PS-IL[X], X = Br−, Cl−, BF4−, and PF6−) supported on imidazolium–styrene copolymers, as well as their catalytic use for the solvent-free synthesis of styrene carbonate from CO2 and styrene oxide, are described. Among the catalysts examined, Zn/PS-IL[Br] was proved to be the most efficient. When used in a homogeneous system during the reaction process, Zn/PS-IL[Br] gave a 97.5% yield of product with a TOF value that can be up to about 3800 h−1. Due to its immiscibility with ethanol, Zn/PS-IL[Br] can be separated like a heterogeneous catalyst through solvent precipitation, and reused at least three times for the reaction without significant loss of activity.

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