Supported mixed-gas fuel cells

It is possible to operate a fuel cell on a single mixture of fuel together with oxygen with the same mixture applied to both electrodes. The symmetry in these so-called mixed-gas fuel cells (MGFCs) is broken by using electrodes with different catalytic properties. It was demonstrated recently that the power density of such cells can be high and approach that of conventional fuel cells. We describe here a simplified configuration of a MGFC supported on a dense, conductive substrate and based on a porous solid electrolyte, which we denote as supported MGFCs (S-MGFCs). We examine a series of combinations of electrodes and both hydrogen and carbohydrates as fuel and their effect on the open circuit voltage of the S-MGFCs formed. It is demonstrated that the open-circuit voltage is in many cases about 50% of the maximum theoretical (Nernst) voltage. The power density, however, is small because of an excessive high internal resistance of the cell.