title: Titanium oxynitride interlayer to influence oxygen reduction reaction activity and corrosion stability of Pt and Pt-Ni alloy.
abstract: A key advancement target for oxygen reduction reaction catalysts is to simultaneously improve both the electrochemical activity and durability. To this end, the efficacy of a new highly conductive support that comprises of a 0.5 nm titanium oxynitride film coated by atomic layer deposition onto an array of carbon nanotubes has been investigated. Support effects for pure platinum and for a platinum (50 at %)/nickel alloy have been considered. Oxynitride induces a downshift in the d-band center for pure platinum and fundamentally changes the platinum particle size and spatial distribution. This results in major enhancements in activity and corrosion stability relative to an identically synthesized catalyst without the interlayer. Conversely, oxynitride has a minimal effect on the electronic structure and microstructure, and therefore, on the catalytic performance of platinum-nickel. Calculations based on density functional theory add insight with regard to compositional segregation that occurs at the alloy catalyst-support interface.
authors.affiliation: Department of Chemical and Materials Engineering, University of Alberta, 9107-116 Street, Edmonton, AB, T6G 2V4 (Canada). xtan@ualberta.ca.
authors.forename: XueHai
authors.initials: X
authors.lastname: Tan
authors.forename: Liya
authors.initials: L
authors.lastname: Wang
authors.forename: Beniamin
authors.initials: B
authors.lastname: Zahiri
authors.forename: Alireza
authors.initials: A
authors.lastname: Kohandehghan
authors.forename: Dimitre
authors.initials: D
authors.lastname: Karpuzov
authors.forename: Elmira Memarzadeh
authors.initials: EM
authors.lastname: Lotfabad
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
authors.forename: Michael H
authors.initials: MH
authors.lastname: Eikerling
authors.forename: David
authors.initials: D
authors.lastname: Mitlin
mesh_terms: D000497:Alloys / Q000737:chemistry*; D002384:Catalysis; D003343:Corrosion; D004563:Electrochemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D009532:Nickel / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D000497:Alloys; D010984:Platinum; D009532:Nickel; D014025:Titanium; D010100:Oxygen
keywords: ab initio calculations; alloys; nickel; oxygen reduction reaction; platinum