Advanced Electrodes for Solid Acid Fuel Cells by Platinum Deposition on CsH2PO4

We demonstrate cathodes for solid acid fuel cells fabricated by vapor deposition of platinum from the metalorganic precursor Pt(acac)(2) on the solid acid CsH2PO4 at 210 degrees C. A network of platinum nanoparticles with diameters of 2-4 nm serves as both the oxygen reduction catalyst and the electronic conductor in the electrode. Electrodes with a platinum content of 1.75 mg/cm(2) are more active for oxygen reduction than previously retorted electrodes with a platinum content of 7.5 mg/cm(2). Electrodes containing < 1.75 mg/cm(2) of platinum show significantly reduced catalytic activity and increased ohmic resistance indicative of a highly discontinuous catalytic-electronic platinum network.