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A hydrogen storage tank based on the metal hydride sodium alanate is coupled with a high temperature PEM fuel cell (HT‐PEM). The waste heat of the fuel cell is used for desorbing hydrogen from the storage tank that in return feeds the fuel cell. ZBT has developed the HT‐PEM fuel cell, Max‐Planck‐Institut für Kohlenforschung the sodium alanate, and IUTA the hydrogen storage tank. During the experiments of the system the fuel cell was operated by load cycling from 165 up to 240 W. Approximately 60 g of hydrogen were delivered from the tank, which was charged with 2676.8 g of sodium alanate doped with 4 mol.% of TiCl3. This amount of hydrogen was desorbed in 3 h and generated a cumulated electrical energy of 660 Wh. In the first cycle 81.5 g of hydrogen were supplied during 3.69 h to the HT‐PEM fuel cell, which was operated nearly constant at 260 W. In the latter case the cumulated electrical energy was 941 Wh.

The rock material pentlandite with the composition Fe4.5Ni4.5S8 was synthesized via high temperature synthesis from the elements. The structure and composition of the material was characterized via powder X-ray diffraction (PXRD), Mössbauer spectroscopy (MB), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and energy dispersive X-ray spectroscopy (EDX). Two preparation methods of pentlandite bulk electrodes are presented. In the first approach a piece of synthetic pentlandite rock is directly contacted via a wire ferrule. The second approach utilizes pentlandite pellets, pressed from finely ground powder, which is immobilized in a Teflon casing. Both electrodes, whilst being prepared by an additive-free method, reveal high durability during electrocatalytic conversions in comparison to common drop-coating methods. We herein showcase the striking performance of such electrodes to accomplish the hydrogen evolution reaction (HER) and present a standardized method to evaluate the electrocatalytic performance by electrochemical and gas chromatographic methods. Furthermore, we report stability tests via potentiostatic methods at an overpotential of 0.6 V to explore the material limitations of the electrodes during electrolysis under industrial relevant conditions.

The aim of the work presented in the current paper was the development of a portable power generation device applying methanol as fuel and fuel cell technology with an electrical net power output of 100 W. At the Institut für Mikrotechnik Mainz (IMM), Germany, an integrated micro-structured methanol fuel processor based on oxidative steam reforming was developed. The fuel processor was tested separately and then coupled to a high-temperature fuel cell that had been developed in parallel by the Zentrum für Brennstoffzellentechnik GmbH (ZBT). ObjectivesPower supply of mobile devices by batteries is time limited, owing to weight restrictions. The increasing energy demand of outdoor applications and wireless industrial tools alone amounts currently to approximately 714 GWh in Europe. Therefore, a potential market exists for alternative solutions such as fuel cell technology. Hydrogen storage by metal hydrides and pressurised hydrogen tanks is not suited as a hydrogen source for portable applications, owing to their weight and market introduction barriers, the latter originating mainly from safety considerations of the end-users. Liquid fuels have a high power density and are easier to handle. Applying fuel processing technology, methanol is converted to a hydrogenrich gas mixture, which is then converted to power in conventional proton exchange membrane (PEM) fuel cells. The main advantage of methanol compared to other liquid energy carriers such as hydrocarbons is the relatively low operating temperature of the reformer reactor. The lower temperature reduces the heat losses, which is crucial in the case of systems operating on a smaller scale.Conventional PEM fuel cells, which are usually operated at about 80°C, show very limited tolerance against carbon monoxide [1]. Even specially developed reformate-tolerant lowtemperature PEM fuel cells are limited to carbon monoxide concentrations of about 100 ppm in continuous operation without rapid degradation effects. Therefore, the high-temperature PEM membrane technology of BASF was chosen, which is capable of tolerating carbon monoxide in the percent range at operating temperatures between 160 and 180°C.The practical demands of an autonomous fuel processor/ fuel cell system of portable scale can be summarised as follows: -Autonomous operation after the system start-up, i.e., the system requires only electrical energy to operate the balance of plant components such as pumps and valves, while the fuel processor is maintained at operating temperature by the combustion of fuel cell anode off-gas or the fuel itself. -Turn-down ratio of about 1:3. -Optimum utilisation of hot process gases at limited system complexity and system costs. -Low time demand for system start-up. -Minimum electrical energy demand for the system start-up. Fundamentals and State-of-the-ArtMethanol is converted at 250-300°C to hydrogen-containing reformate by steam reforming [1]: CH 3 OH + H 2 O → 3 H 2 + CO 2 DH 0 = 59 kJ/mol (1)

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