TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Membrane: In the ion exchange membrane above, the material capable of eliminating free radicals is selected from salts, oxides, hydroxides and complexing materials of manganese (Mn), cerium (Ce) or lanthanum (La) elements or its combinations. The cerium salt is selected from cerium nitrate (Ce(NO3)2), cerium acetate (Ce(Ac)3), cerium carbonate (Ce2(CO3)3), cerium sulfate (Ce2(SO4)3), cerium phosphate (CePO4), Ce(NO3)4, Ce(SO4)2, (NH4)2Ce(NO)6 and LaCe(CO3)3 or its combinations. Manganese salt is selected from manganese nitrate (Mn(NO3)2), manganese acetate (Mn(Ac)2), manganese carbonate (MnCO3), manganese sulfate (MnSO4), manganese phosphate (Mn3(PO4)2), MnPO4, Mn(CO3)3 and Mn2(SO4)3 or its combinations. Lanthanum salt is selected from lanthanum phosphate (LaPO4), lanthanum acetate (La(Ac)3), lanthanum acetate (La2(CO3)3) and lanthanum sulfate (La2(SO4)3) or its combinations. The oxide or hydroxide is selected from cerium (III) oxide (Ce2O3), cerium (IV) oxide (CeO2), manganese (ii) oxide (MnO), manganese (III) oxide (Mn2O3), lanthanum oxide (La2O3), cerium hydroxide (Ce(OH)3), Ce(OH)4, manganese hydroxide (Mn(OH)3) and lanthanum oxide (La(OH)3) or its combinations. The oxides are selected from any two or three of the oxides of cerium, manganese or lanthanum or the mixtures of them and other elements, or are oxides composed of any two of cerium, manganese or lanthanum elements and other elements. Mixing oxides or the oxides with calcium-titanium structures are CexTi(1-x)O2 (x=0.25-0.4), Ca0.6La0.27TiO3, La(1-y)CeyMnO3 (y=0.1-0.4), or La0.7Ce0.15Ca0.15MnO3. Oxides are carried on the auxiliary proton conducting materials, which are one of silicon oxide (SiO2), zirconium oxide (ZrO3), zirconium phosphate (Zr3(PO4)4), H3PW12O14, cesium bisulphate (CsHSO4), zirconium biphosphate (Zr(HPO4)2), HZr2(PO4)3 or Zr2H(P3O10)2 or its combinations. The ligand of the complexing material is cyclodextrin, ether, acetylacetone, nitrogen-containing ether, EDTA, dimethylformamide (DMF) or dimethylsulfoxide (DMSO).