The reaction of iron with steam produces pure hydrogen, which can be directly used in polymer electrolyte fuel cells for power generation. Therefore iron, in its elemental form, can be used as a hydrogen storage and purification material. Besides thermodynamic properties, the hydrogen reception and release rate of the process are of special interest. To determine the reaction characteristics of iron contact mass for the first charging and discharging cycle, thermogravimetric analysis was used in the temperature range of 500-1000 degrees C. The influences of contact mass composition, reaction temperature, and gas composition on the redox reactions were determined. Contact masses with highly alkaline composition show faster reaction with steam at elevated temperatures. Acidic sample compositions accelerate the reduction with hydrogen at lower temperatures. The influence of hydrogen partial pressure and the suitability of methane, carbon monoxide, and synthesis gas for the contact mass reduction have been investigated intensely. Methane reduces the contact mass only at temperatures higher than 800 degrees C at an acceptable rate, but always leads to carbon deposition. Also, the operation with CO/H-2 mixtures results in carbon formation on the contact mass as soon as iron is present, whereby the rate of carbon production strongly depends on reaction temperature and gas composition. The product gas from steam reforming of methane is found to be a promising option as a reduction gas, leading to no carbon formation on the pellets at temperatures above 720 degrees C.