Surface composition of magnetron sputtered Pt-Co thin film catalyst for proton exchange membrane fuel cells

摘要: Abstract Recently we have tested a magnetron sputtered Pt-Co catalyst in hydrogen-fed proton exchange membrane fuel cell and showed its high catalytic activity for the oxygen reduction reaction. Here present further investigation of thin film by both experimental theoretical methods. Scanning electron microscopy transmission experiments confirmed nanostructured character catalyst. The surface composition as-deposited annealed at 773 K films was investigated analysis techniques, such as synchrotron radiation photoelectron spectroscopy X-ray spectroscopy. Modeling based on density functional theory that 6 nm large 1:1 nanoparticles is almost exclusively composed Pt atoms (>90%) typical operation conditions Co content does not exceed 20% 773 K, agreement with characterization vacuum. According to experiment, valence states nanostructures shifted 0.3 eV higher energies, which can be associated their changes electronic structure caused alloying are also reflected measured 4f, 3p 2p peak binding energies.