Titanium hydride was used for foaming the aluminium casting alloy AlSi6Cu4. In order to improve foaming characteristics the TiH 2 powder was subjected to various heat treatments prior to processing to shift hydrogen release up into the melting range of the alloy. Untreated and pre-treated powders were characterised by oxygen analysis, thermal analysis in connection with mass spectrometry applying various temperature profiles, X-ray diffraction and transmission electron microscopy. In addition, foaming trials were carried out based on various TiH 2 powders. It was found that oxidation of TiH 2 particles is responsible for the observed shift in decomposition temperature since heating under argon did not produce this effect. The shift can be tailored by choosing suitable pre-treatment parameters. For an appropriate choice a beneficial effect on foam morphology was found.

A 5% Ni/MnO catalyst has been tested for the dry reforming of methane at different temperatures and reactant partial pressures. Changing the reactant ratio with time on stream results in a decrease in the deactivation rate of the catalyst. Graphitic carbon growth and metal particle sintering have been observed by applying in situ transmission XRD using synchrotron radiation under actual reaction conditions. Both methane and carbon monoxide separately result in graphitic surface carbon, which can then be oxidized by carbon dioxide. The morphology of the surface carbon has been analyzed by TEM, and the reactions of both methane and carbon monoxide result in the same graphitic multiwalled carbon nanotubes. The present combination of catalytic experiments and in situ techniques suggests that surface carbon acts as an intermediate in the formation of CO and that catalyst deactivation happens via metallic particle sintering. These results enable a more rational choice of reaction conditions to ensure high catalyst activity and long-term stability. Future catalyst advances must aim to prevent metal particle sintering.

Li-doped MgO was prepared on different preparative routes and with different loadings. The catalytic activity was found to decay for all catalysts for 40 h time on stream. A detailed structural analysis of 0.5 wt% Li-doped MgO showed heavy losses of Li, reduced surface area and grain growth. A correlation between these factors and the deactivation could not be found. The reaction temperature and the flow rate were found to be the main deactivation parameters.

Results concerning the coupling of the steam reforming (SR) and total oxidation (TOX) of methanol in a two-passage reactor are presented. A commercially available copper based catalyst is used for the steam reforming. For the total oxidation, a highly active cobalt oxide catalyst was developed. Both catalysts are used in form of thin layers immobilized on the wall of the micro-channels. Reactor design and operating conditions are based on kinetic models developed under isothermal conditions in micro-structured reactors. For the oxidation reaction, complete conversion of methanol (>99%) at temperatures higher than 250 • C is observed. For the steam reforming, the hydrogen and CO 2 selectivity is higher than 96% for methanol conversion up to 90%. Besides the steady state, the dynamic behavior of the coupled system is studied. It is shown that the transient behavior is mainly determined by the thermal inertia of the system.

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