NER: Water Electrolysis using Nanostructured Electrodes- An Efficient Approach to Hydrogen Production

Rensselaer Polytechnic Institute, Troy NY

Investigators

Abstract

Abstract Proposal Title: NER: Water Electrolysis Using Nanostructured Electrodes- An Efficient Approach to Hydrogen Production Proposal Number: CTS-0609006 Principal Investigator: Nikhil Koratkar Institution: Rensselaer Polytechnic Institute Abstract: The aim of this NER project is to investigate the feasibility of using nanostructured electrodes to efficiently produce hydrogen in water electrolysis cells. The major drawback of conventional water electrolyzers is high over-potential losses at the cell electrodes leading to large electricity consumption making such systems prohibitively expensive to operate. The enhanced surface area (or wetted area) of nanostructured electrodes coupled with large electric field amplification effects could dramatically reduce over-potential losses at the electrodes and significantly lower energy consumption for water electrolysis. The objective for this project is to explore the fundamental mechanisms by which nanostructured electrodes may be used to improve performance and to quantify the performance benefits that result from their r use. The PIs will study water electrolysis using an array of Ruthenium (Ru) nano-rods as cathode and a planar Ru film as anode. Preliminary results were extremely promising;they showed a 50% reduction in over-potential loss by using nanostructured electrodes. This NER project is focused upon developing a better understanding of the basic mechanisms using nanorods by performing a series of carefully designed control experiments. For example- to study the correlation between electrode area and over-potential loss, they will systematically vary the electrode surface area (by controlling nanostructure length). To study the effect of electric field on the over-potential, they propose to control the curvature of the nanostructure tip; and specifically they will compare performance of flat-top (zero curvature) Ru nanorod arrays with atomically sharp (pyramidal tip-apex) Ru nano-rod arrays. To study the electric field effect we will also compare the performance of a pyramidal apex tip Ru nano-rod array with that of a planar (flat) Ru film with the same electrochemically active area. We also propose to study the effect of cell geometry, electrode composition and temperature on the nanostructured electrolyzer's performance. The experiments proposed in this project will enable an understanding of the fundamental processes that control the a nanostructured electrolyzer's response and could catalyze rapid and innovative advances leading to the development of high efficiency and low power nanostructured water electrolysis units. From a broader impacts perspective, the hydrogen economy will require readily available and affordable hydrogen fuel. Current methods of hydrogen production do not fulfill these requirements. A novel water electrolyzer system (featuring nanostructured electrodes) that could efficiently produce hydrogen with reduced energy consumption is proposed. Importantly the proposed approach is environmentally clean and no harmful waste products are released into the atmosphere (e.g. no CO2 emissions). The proposed work shows potential to significantly advance hydrogen production technology- paving the way for national energy independence, which is the grand challenge for the 21st century. To integrate their research discoveries with education they will develop special interactive learning modules (ILMs) and incorporate them into the curriculum at Rensselaer. These ILMs or "Virtual-Labs" will also be presented to high school students and teachers from the New Visions Program to help popularize science and to attract underrepresented groups to careers in science and engineering. This project will also involve active participation of undergraduate students in research activities and in the design and development of the proposed interactive learning modules.