A Facile Microfluidic Hydrogen Peroxide Fuel Cell with High Performance: Electrode Interface and Power-Generation Properties

To simplify the miniature fuel cell structure and flow mode, we report here a microfluidic fuel cell running on H₂O₂ as both fuel and oxidant under acidic conditions. Prussian blue coating on carbon paper serves as the cathode side while the anode is made of three-dimensional flow-through Ni foam. The fuel cell achieves a power density in excess of 0.58 ± 0.13 W m^-2 at a current density of 3.68 ± 0.1 A m^-2, and an open circuit potential of 0.65 V. Importantly, the Ni foam shows a corrosion in H₂O₂-catalyzing after a long-term operation, which is seriously neglected by most of previous H₂O₂-running fuel cells. SEM images and XPS spectra demonstrate a gradient corrosion occurs in the three-dimensional flow-through porous Ni-foam electrode. The corrosion degree of Ni foam gradually aggravates along the vertical direction, which is caused by the gradient accumulation of H₂O in the porous electrode. The protection methods including surface coating a protection layer and doping some more reactive metals have been proposed to improve the system commercialization.