Methanol is considered a promising liquid fuel in context
with electrochemical energy conversion and storage for
mobile applications. It is shown here that a direct methanol
fuel cell can be used for spontaneous charging and discharging
a supercapacitor (SC) for intermediate storage of chemical
energy. Thereby, protons and electrons of the methanol-
derived hydrogen are stored separately in the electrical
double layer of the SC electrode. The charging and discharging
of this fuel cell–SC hybride device is investigated in
experiments of spontaneous conditions (closed circuit) and
also under externally enforced constant voltage sweep rate (cyclic voltammetry) and under constant current conditions.
Alternatively, gas phase hydrogen is generated from methanol
in an electro-reforming process. When more efficient
anode electrocatalysts become available this may become
the method of choice for on-board and on demand hydrogen
production in mobile applications.