My research group have discovered a series of dinuclear catalysts which show good activity, control and high selectivity in the alternating copolymerization of carbon dioxide and epoxides to produce polycarbonates. The ring opening copolymerization (ROCOP) of CO2 and epoxides provides a useful method to make aliphatic polycarbonates and allows 30-50% reduction in petrochemical raw materials by substitution with carbon dioxide. Our team synthesize dinuclear metal complexes, typically featuring Zn(II), Mg(II) and transition metals, which are highly efficient catalysts even using low pressures of carbon dioxide. The catalysts are even active at 1 bar pressure of CO2 and show a high tolerance to common contaminants, such as water. We have recently demonstrated that these catalysts can even copolymerize carbon dioxide captured from a UK power station to deliver polycarbonate polyols suitable for polyurethane production. In 2015, our group reported a heterodinuclear catalyst, featuring both Zn(II) and Mg(II) coordinated by a symmetrical macrocycle; it shows better activity than either homodinuclear analogues or combinations of them.