Currently, Ash-free clean coal producing process by solvent extraction is under development. The produced ash-free clean coal can be directly combusted in a gas turbine which results in substantial improvement of power generation efficiency. However, the clean coal produced by the solvent extraction still contain trace amount of alkali metal which may cause corrosion on turbine blades during the direct combustion. In present work α,β-metal (Zr and Ti) phosphates and H-Y zeolite were synthesized and their ion exchange characterizations were investigated for the application on alkali metal removal for clean coal production. Na+ ion removal capacities of the metal phosphates and H-Y zeolite were measured and compared in both aqueous solution (100 ppmw, Na+) and coal dissolved N-methyl-2-pyrrolidone (NMP, 12 ppmw Na+) at elevated temperature. In aqueous solution, the β form metal phosphates showed very high ion exchange capacities compared to α form. β form metal phosphates also showed higher Na+ removal capacities than H-Y zeolite. In ion exchange medium of NMP, all the α form metal phosphates showed over 90% of Na+ ion removal efficiency in the temperature range of 200 to 400 while that of H-Y zeolite decreased as a half when the temperature was over 350. In addition, the regenerated metal phosphates by acid treatment showed no sign of degradation in Na+ removal efficiency. Among the metal phosphates used, Zr0.75Ti0.25 (HPO4)2 showed the best performance in Na+ removal and is expected to be the most suitable inorganic ion exchanger for the alkali metal removal process.