Diversified electro-membrane processes utilizing cation exchange membranes (CEMs) are expensive and require low electricity consumption due to its high conductive and stable nature even in strong acidic or oxidative environment. CEMs are membrane separator used in diversified electro-membrane processes including: electrodialysis (water desalination, separation of inorganics from organic molecules, separation of specific inorganic ion, etc), electrolysis ( used as separator for chlor-alkali process, production of HI by Bunsen reaction of iodine−sulfur (I−S) process, electrochemical catalytic water splitting), electro-electrodialysis for in-situ ion exchange and ion substitution, electro-deionization for producing ultrapure water, and polymer electrolyte membrane for fuel cell applications.