Microstructured cathode for self-regulated oxygen generation and consumption

A fuel cell is disclosed with a self-regulated oxygen supply used in conjunction with a self-pumping fuel supply (e.g., a self-pumping anode). The cathode side of the fuel cell includes a gas diffusion electrode interposed between the fuel chamber and the oxidant chamber (e.g., H2O2), the gas diffusion electrode having a catalyst layer formed thereon. An oxygen gas capturing substrate is disposed in the oxidant chamber and is spaced apart from the gas diffusion electrode. The gas capturing substrate has first and second sides containing a plurality of holes extending there between. The first side of the substrate faces the oxidant and the second side faces the gas diffusion electrode. The substrate contains a catalyst on the second side of the substrate or within an inner surface of the holes.