Sulfonated polystyrene-block-(ethylene-ran-butylene)-block-polystyrene (SPSEBS) membrane for sea water electrolysis to generate hydrogen Subbiah Ravichanran a* , Rengarajan Balaji a , Balasingam Suresh Kannan a , Swaminathan Elamathi b , Dharmalingam Sangeetha b , Jothinathan Lakshmi a , Subramanian Vasudevan a and Ganapathy Sozhan a , a Electro Inorganic Chemicals Division, Central Electrochemical Research Institute (CSIR), Karaikudi-630006, India. b Department of Chemistry, Anna University, Chennai-600025, India. Sea water oxidation is one of the promising ways to produce hydrogen since it is available in plentiful supply on the earth. However, in sea water electrolysis poisonous chlorine evolution is the most favored reaction over oxygen evolution at the anode. In this work, study has been focused on the development of electrode materials with high selectivity for oxygen evolution reaction over chlorine evolution. We employed perm selective membrane i.e. sulfonated polystyrene-block-(ethylene-ran-butylene)-block- polystyrene (SPSEBS) which electrostaticlly repels the chloride ion (Cl - ) to the electrode surface and thereby enhances the oxygen evolution and reduces the chlorine evolution at the anode. The electrochemical behavior of both modified and bare IrO 2 electrodes were characterized using polarization studies and the gas evolution efficiencies are calculated based on bulk electrolysis method. The surface morphology of the electrode was analyzed before and after electrolysis using scanning electron microscope (SEM). The results suggest that the nearly 95% oxygen evolution efficiency could be achieved when the surface of IrO 2 /Ti electrode was modified with perm selective membrane. Introduction Hydrogen has great potential as an environmentally clean energy fuel and as a way to reduce the reliance on imported energy sources. Before hydrogen can play a bigger energy role and become a widely used alternative to fossil fuel, many new facilities and systems must be built for energy production without delay. Since, when it is utilized (either in fuel cells or IC engines) the only by-product generated is water. Besides, hydrogen is available in both renewable (water) and non-renewable (fossil fuel) forms. However, the existing hydrogen production from non-renewable sources is inadequate to sustain its extensive use for energy purposes. Hence, effective generation of hydrogen from renewable sources is essential for the so-called hydrogen economy [1-2]. While hydrogen can be produced by several methods, water electrolysis is a clean and ECS Transactions, 33 (27) 157-166 (2011) 10.1149/1.3565511 ©The Electrochemical Society 157 ecsdl.org/site/terms_use address. Redistribution subject to ECS license or copyright; see 114.70.4.5 Downloaded on 2013-04-22 to IP