An exceedingly rare three-dimensional CO2-coordinated inorganic polyoxoanion was prepared by a hydrothermal synthesis reaction. The CO2 ligand connects with two Zn-ε-Keggin cores in a linear and symmetrical μ2-η2o,o coordination pattern with a C[double bond, length as m-dash]O bond length of 1.099(112) Å. The new compound reported here exhibits not only appealing structures but also high catalytic activity for the cycloaddition of carbon dioxide with epoxides.