Role of Nuclear Based Techniques in Development and Characterization of Materials for Hydrogen Storage and Fuel Cells

Today various materials for fuel cell applications are urgently needed, including potential electrodes for the molten carbonate fuel cells. Identification of appropriate storage concepts are also urgently needed in order to initiate necessary steps for implementation of such technologies in daily life. Recent progress in nuclear analyses and observation/imaging techniques can significantly contribute to a successful achievement of ongoing research challenges. Primary importance is given to areas of characterization and in-situ testing of materials and/or components of hydrogen storage and fuel cell systems. Dedicated attention is addressed to issues related to hydrogen storage concepts, such as metal hydrides and other systems (e.g. fullerene structures) as well as their stability and the changes induced by hydrogen sorption process. In total 14 papers report on various scientific and research issues related to hydrogen storage and conversion technologies. Based on presented results, it can be concluded that nuclear- based techniques, specifically those involving neutrons, X rays and particle beams, play very important roles in ongoing research activities among many IAEA Member States. A short overview of individual reports is summarized below. The presented papers give an overview of typical applications of such techniques and their experimental setups based either on X ray or neutron sources, which can be used effectively to study specific properties of materials for hydrogen storage as well as microstructural features and hydrogen interaction with solid matter. The papers presented by Canadian, Dutch, Italian and Norwegian groups, report on research results related to application of thermal neutron scattering and neutron diffraction in studies of hydrogen containing materials, particularly in situ characterization as a means to study metal hydrides' structure and their modification upon hydrogen sorption. The investigation on solid state hydrogen storage materials studied by a combination of complementary methods was presented by a team from the Joint Research Centre of European Commission, which was in charge of coordination work among various research groups from France, Germany and the United Kingdom. They reported effective combination of neutron, X ray and other analytical nuclear techniques as well as a brief comparison of the advantages and limitations of individual methods. Special emphasis was given to characterization of the microstructural changes and thin films made by available nuclear methods, such as positron annihilation spectroscopy and neutron reflectometry. The following report by Chinese researchers, gave a short update on hydrogen absorption properties of lanthanum and zirconium- based hydrogen storage materials. Argentinean and Croatian scientists reported on the degradation of a PEM, fuel cell, platinum-based catalyst by PIXE and application of ERDA methods for imaging of hydrogen-implanted silicon, respectively. The investigation of irradiation effects on oxygen, water and CO2 desorption, and the identification of phase-transformation behavior on increasing temperature were also discussed. A short overview of structural transformations in Fullerite C60 due to hydrogenation was reported by Ukrainian researchers. Finally, the study of proton conductors, irradiated by neutrons was presented by the Kazakhstani research team. Briefly discussed was the problem of proton conducting ceramics and the hydrogen concentration profile using ion beam analysis to probe the relationship between microstructure and hydrogen diffusion. Generally, this publication aims to contribute to the dissemination of information regarding practical application of nuclear based techniques in research related to R and D initiatives on hydrogen based energy systems, in particular conversion and storage technologies. (author)