In a first attempt, we still recognized the ignition of the catalyst during operation, which could be critical due to the high heat capacity of the aluminum jackets leading to a time delay of minutes when it is necessary to reduce the heating temperature. In order to ensure safe operation, the higher catalyst activity was therefore not just compensated by a lower specific reaction volume to surface ratio, but further decreased by dilution of the catalyst bed. These safety measures are necessary for the present initial proof-of-concept lab experiments, but can be omitted in later stages of the technology development.