tetrahydroborates; borane; hydrogen; storage; mechanism; sorption; hydrogen storage; complex hydrides; synthesis
Remhof A, Borgschulte A, Friedrichs O, Mauron P, Yan Y, Zuttel A (2012), Solvent-free synthesis and decomposition of Y(BH4)(3), in SCRIPTA MATERIALIA
, 66(5), 280-283.
Remhof Arndt, Yan Yigang, Friedrichs Oliver, Kim Ji Woo, Mauron Philippe, Borgschulte Andreas, Wallacher D., Buchsteiner A., Hoser A., Oh K. H., Cho Y. W., Züttel Andreas (2012), Towards room temperature, direct, solvent free synthesis of tetraborohydrides, in Journal of Physics: Conference Series
, 340, 1-8.
Borgschulte A, Callini E, Probst B, Jain A, Kato S, Friedrichs O, Remhof A, Bielmann M, Ramirez-Cuesta AJ, Zuttel A (2011), Impurity Gas Analysis of the Decomposition of Complex Hydrides, in JOURNAL OF PHYSICAL CHEMISTRY C
, 115(34), 17220-17226.
In the project the influence of boron-hydrogen compounds on the formation and decomposition of tetrahydroborates is analyzed. The main objective is to understand the related mechanisms based on reactions of hydrogen/borane uptake and release. The understanding of these mechanisms will serve as a basis for optimization of tetrahydroborates to be used in hydrogen storage. Characterizations by different complementing techniques will give new insights on structural, chemical, kinetic and thermodynamic properties of the system and its evolution during gas uptake and release. Apart from investigations on the mechanisms, a new way of synthesis of tetrahydroborates is investigated and optimized. Since tetrahydroborates are widely applied reagents in organic and inorganic synthesis, this invention is of particular interest for the chemical industry. It will be protected by a patent. With respect to hydrogen storage a main goal is to find a catalyst, which promotes hydrogen and prevents borane release of tetrahydroborates at low temperatures. The hydrogen storage material looses B irreversibly via gaseous BHx, which is then missing for a re-absorption process. Furthermore, the emitted diborane is difficult to handle, since it is a toxic gas. Hence the prevention of the formation of borane is a main step towards reversible hydrogen storage in tetrahydroborates at low temperature, which is mandatory for future automotive applications. During the project I want to determine and evaluate the kinetics and thermodynamics of processes involving boranes and answer questions about reaction mechanisms and mass transport in the material. The synthesis I am going to perform is exposing metal hydrides to diborane atmosphere under heating and/or milling conditions. Thereby I want to shed light onto the reaction processes, whenever possible by “in situ” methods including Raman spectroscopy, X-ray diffraction, differential scanning calorimetry, neutron diffraction and gravimetric/volumetric measurements. By our recently developed “controllable reactive milling device”, we have the unique possibility to perform “in situ” kinetic and thermodynamic analysis under high energy milling conditions in vacuum, hydrogen or borane atmosphere. For the decomposition reaction we focus on the thermal desorption of tetrahydroborates monitored by thermal mass spectrometry. In addition we will analyze the influence of additives known for promoting the decomposition of diborane.