Palladium Alloy Based Nanocomposite as an Efficient Anode and Cathode Electrocatalyst for Polymer Electrolyte Membrane Fuel Cell

Thursday, 5 October 2017: 17:40
National Harbor 2 (Gaylord National Resort and Convention Center)
C. Priji and S. Ramaprabhu (Indian Institute of Technology Madras)
Polymer electrolyte membrane fuel cell (PEMFC) has the capacity to efficiently convert chemical energy into electrical energy to meet the future energy requirements. High efficiency, zero pollution, low operating temperature and fast start-up time are the advantages of hydrogen based PEMFC, which makes it a promising candidate for transportation and portable applications. Platinum and platinum alloy based nanomaterials are the most commonly used electro-catalysts for both hydrogen oxidation reaction (HOR) as well as oxygen reduction reaction (ORR) in PEMFC due to its high catalytic activity and resistance to corrosion. However, the commercialization of PEMFC has been hindered by the high cost of platinum and less abundance. Hence, platinum free electrocatalysts with comparable activity have been widely investigated. Investigations of Palladium based electrocatalyst suggest that it is a good alternative for platinum based electrocatalyst. Further, the reduction in the cost of catalyst can be achieved by alloying palladium with transition metal. Furthermore, to achieve high catalytic activity, significant advances in catalyst support materials and proper utilization of catalysts are still needed. The complete utilization of the catalyst can be achieved by choosing a good support material with high surface area and good electrical conductivity. With the goal of reducing the cost of electrocatalyst with a good fuel cell performance, present work is focused on the preparation of palladium-transition metal (Pd-TM) alloy nanoparticles supported on partially exfoliated carbon nanotubes (PCNT) as an efficient anode as well as cathode electrocatalyst. PCNT has the combined structure of 1D multiwalled carbon nanotubes and 2D graphene and shows a synergistic effect of good conductivity and high surface area. The improvement in electrical conductivity helps in quick electron transport while enhancement in surface area provides the more anchoring sites to disperse catalyst nanoparticles. Figure 1 shows the TEM image of Pd-TM alloy nanoparticles supported on PCNT. It shows uniform dispersion of catalyst nanoparticles on the support material. Both half-cell and full cell measurements were carried out with this material and it showed significant performance. Pd-TM alloy/PCNT nanocomposite prepared in the present work exhibits good HOR and ORR activity and the work discusses the approach and the results.