Iron oxides represent a substantial fraction of secondary minerals and particularly affect the reactive properties of natural systems in which they formed, e.g. in soils and sediments. Yet, it is still obscure how transient conditions in the solution will affect the properties of in situ precipitated Fe oxides. Transient compositions, i.e. compositions that change with time, arise due to predominant non-equilibrium states in natural systems, e.g. between liquid and solid phases in soils. In this study, we characterize Fe-OM co-precipitates that formed in pH-neutral exfiltrates from anoxic topsoils under transient conditions. We applied soil column outflow experiments, in which Fe 2+ was discharged with the effluent from anoxic soil and subsequently oxidized in the effluent due to contact with air. Our study features three novel aspects being unconsidered so far: 3

Nanocrystallization is known to yield several improvements for the storage and uptake rate of hydrogen in solids. Usually this process is achieved by ball milling to produce a nanopowders. However, handling of these powders is risky and difficult, and there is also a high risk of introducing impurities into the storage material. In this situation materials processed by Severe Plastic Deformation (SPD) yield several advantages: (i) the materials are produced in bulk shape with 100% density; (ii) the introduction of impurities is minimized, (iii) in addition to additional grain boundaries, many dislocations and particularly vacancies are generated which may further improve the hydrogen storage capacity and kinetics.

hydrous point defects in the structure of triphylite and/or sarcopside, which are possible under the assumption of vacancies at the Li (M1) and/or P sites.

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