Electrochemical behaviour of tetrachloro and tetrabromo uranyl complexes in room temperature ionic liquids

► The reduction of the tetrahalo uranyl complexes is studied in ionic liquids. ► An Electron Transfer - Chemical reaction - Electron transfer mechanism is proposed. ► The assumed final product is a U(IV) deposit. ► The stability of the intermediate [UO2X4]3− depends on the ligand and the ionic liquid.