title: Enhancement Effect of Noble Metals on Manganese Oxide for the Oxygen Evolution Reaction.
abstract: Developing improved catalysts for the oxygen evolution reaction (OER) is key to the advancement of a number of renewable energy technologies, including solar fuels production and metal air batteries. In this study, we employ electrochemical methods and synchrotron techniques to systematically investigate interactions between metal oxides and noble metals that lead to enhanced OER catalysis for water oxidation. In particular, we synthesize porous MnOx films together with nanoparticles of Au, Pd, Pt, or Ag and observe significant improvement in activity for the combined catalysts. Soft X-ray absorption spectroscopy (XAS) shows that increased activity correlates with increased Mn oxidation states to 4+ under OER conditions compared to bare MnOx, which exhibits minimal OER current and remains in a 3+ oxidation state. Thickness studies of bare MnOx films and of MnOx films deposited on Au nanoparticles reveal trends suggesting that the enhancement in activity arises from interfacial sites between Au and MnOx.
authors.affiliation: Department of Chemical Engineering, Stanford University , 443 Via Ortega, Stanford, California 94305, United States.
authors.forename: Linsey C
authors.initials: LC
authors.lastname: Seitz
authors.affiliation: Department of Chemical Engineering, Stanford University , 443 Via Ortega, Stanford, California 94305, United States.
authors.forename: Thomas J P
authors.initials: TJ
authors.lastname: Hersbach
authors.affiliation: SLAC National Accelerator Laboratory , 2575 Sand Hill Rd, Menlo Park, California, 94025, United States.
authors.forename: Dennis
authors.initials: D
authors.lastname: Nordlund
authors.affiliation: Department of Chemical Engineering, Stanford University , 443 Via Ortega, Stanford, California 94305, United States.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Jaramillo
keywords: MnOx; metal air batteries; oxygen evolution reaction; solar fuel production; water oxidation