Catalytic Effect of Different Hydroxyl-Functionalised Ionic Liquids Together with Zn(II) Complex in the Synthesis of Cyclic Carbonates from CO2

•Several hydroxyl-functionalised quaternary ammonium salts were used as catalysts in the coupling reaction between CO2 and epoxides.•The effect of a hydroxy-isopropyl substituent was studied for the first time and revealed to have a positive effect in the reaction kinetics.•The best catalytic activity was attained when both effects (electrostatic and hydrogen bonding) were combined.