Symposium 2.5



(3 sessions)


Hydrogen, energy, geochemistry, recovery, recycling, substitution of rare elements, life cycle analysis, batteries, fuel cells, electrolysis, oligo-elements for energy conversion


Thierry LEMERCIER (Solvay, Brussels, BE), Elsa OLIVETTI (Dept of Materials Science and Engineering, MIT, Cambridge, USA), Alain PRINZHOFER (GEO4U/BR, IPGP Paris, FR), Lauriane D’Alençon (Solvay, Paris, FR)



Among the 17 sustainable development goals (SDG), adopted by the UN 70th general assembly in December 2015, SDG 7 “Ensure access to affordable, reliable, sustainable, and modern energy for all”, SDG 12 “Ensure sustainable consumption and production patterns” and SDG 13 “Urgent action to combat climate change” can be translated into the problem of an optimal management of natural resources in energy and raw materials. 

Our planet faces formidable energy challenges, but great hopes are placed on the use of renewable energies such as wind, wave and sun which can generate huge amounts of electricity. The increasing deployment of photovoltaic/wind farms, of electrochemical energy storage units and of transition lines will call for huge amounts of materials. This triggers severe concerns about materials availabilities and global reserves, and raise questions about recycling. Life Cycle Analysis (LCA) studies will undoubtedly become more important in the next decades. Chemical elements of interest are i) 4d and 5d transition metals of groups 8 to 10 used in catalysis for energy production as well as depollution, ii) rare earths used in electronic components and magnets, and iii) elements used in mobile and stationary batteries. Noble gases, and particularly He are of increasing technological importance, while known sources and reserves are quite limited and geographically scarce. 

A special focus will be given on the increasing use of H2 as a pillar of this global energy challenges, more and more called “the hydrogen economy”.  Hydrogen will be an energy vector and a starting chemical resource massively produced from renewable and intermittent electricity (sun, wind, tides…) as “power to gas” or “power to chemicals” concepts. Such approaches will allow a better match between a day to day and inter-seasonal offer and demand. Advances in earth abundant materials involved in H2 production by electrocatalytic, photovoltaic or photo-catalytic water splitting, should therefore be considered. Besides H2 produced from solar energy, natural hydrogen sources [1] might significantly contribute to the energy landscape.

This symposium should also allow review the questions related to origins and reserves, geological contexts, fluxes and exploitation strategies of natural H2. A fresh geochemical look at this problem is very relevant, all the more as natural H2 sources have been identified with significant concentrations in He.  This symposium will therefore call for original researches showing i) the multifaceted aspects of chemical recovery processes of energy-related materials so as to revitalize the image of “recycling chemistry”, too frequently associated to an old and boring chemistry, ii) the development of models to forecast the worldwide materials reserves under various scenarios, iii) novel LCA models to predict which development scenario is the most sustainable, iv) contributions covering geochemical, extractive and processing aspects of renewable energy-related material resources, v) novel energy storage or catalytic materials involving earth abundant elements, vi) essential rare elements savings, towards the concept of “oligo-elements for energy conversion”, like oligo-elements are involved in biological functions, which is also a solution to manage the resources in a sustainable way.    


[1] V. Larin et al., Natural Molecular Hydrogen Seepage Associated with Surficial, Rounded Depressions on the European Craton in Russia, Natural Resources Research, DOI: 10.1007/s11053-014-9257-5, Published online 15 November 2014.