The search for materials of high hydrogen capacity and reversibility has focused over the last two decades on the hope that complex hydrides based on light elements including lithium, boron, nitrogen and aluminium could potentially deliver hydrogen with storage capacities up to 19.6 mass %. However, key problems associated with the properties of these materials including their high temperature for hydrogen release and their lack of ability for easy hydrogen uptake has reduced hopes to achieve practical materials from these light elements. Typical high capacity complex hydrides including LiAlH4 have remained irreversible upon direct exposure to hydrogen pressure. Reactive mixing of hydrides can lead to some improvements, but the complexity of the reactions involved and side reactions significantly impact their hydrogen properties, and ultimately defeat the idea of achieving high hydrogen capacity. Indirect paths for off-board hydrogen regeneration of many irreversible hydrides have been elegantly devised. But ideally, paths for direct hydrogen uptake should be found to enable the practical use and uptake of high capacity complex hydrides as a viable technology.
In this talk Associate Professor Aguey-Zinsou reviews the search through the nanoscale approach and findings in the existence of direct hydrogen reversibility paths in common metal and complex hydride systems including LiH, AlH3, LiAlH4, and boron containing compounds. In particular, findings of reversibility paths in several systems at the nanoscale bring hopes that ways to design hydrogen release/uptake mechanisms from high capacity complex hydrides should be feasible as well as new applications toward advanced catalysis and battery technologies.
About Kondo-Francois Aguey-Zinsou
Associate Professor Kondo-François Aguey-Zinsou received a Master in Surface and Interface Sciences in 1997, and completed a PhD in heterogeneous catalysis at the University Pierre et Marie Curie (Paris, France) in 2000. He carried-out postdoctoral research at the University of Queensland (Australia) in bio-electrochemistry. In 2003, he joined the research centre GKSS in Hamburg (Germany) and worked on the development of advanced materials for hydrogen storage. In 2005, he moved to Queen Mary University London, and later on to University College London (UK) where he supervised research projects on hydrogen storage, biofuel cells, and biomaterials. Since 2009, he has joined the School of Chemical Sciences and Engineering at the University of New South Wales (Sydney, Australia). His current research focuses on the physical-chemistry of light metals and their hydrides at the nano-scale.