Novel options and limitations of methanol-based production and storage for mobile applications

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.