title: Effect of Sb Segregation on Conductance and Catalytic Activity at Pt/Sb-Doped SnO2 Interface: A Synergetic Computational and Experimental Study.
abstract: Antimony-doped tin dioxide (ATO) is considered a promising support material for Pt-based fuel cell cathodes, displaying enhanced stability over carbon-based supports. In this work, the effect of Sb segregation on the conductance and catalytic activity at Pt/ATO interface was investigated through a combined computational and experimental study. It was found that Sb-dopant atoms prefer to segregate toward the ATO/Pt interface. The deposited Pt catalysts, interestingly, not only promote Sb segregation, but also suppress the occurrence of Sb(3+) species, a charge carrier neutralizer at the interface. The conductivity of ATO was found to increase, to a magnitude close to that of activated carbon, with an increment of Sb concentration before reaching a saturation point around 10%, and then decrease, indicating that Sb enrichment at the ATO surface may not always favor an increment of the electric current. In addition, the calculation results show that the presence of Sb dopants in ATO has little effect on the catalytic activity of deposited three-layer Pt toward the oxygen reduction reaction, although subsequent alloying of Pt and Sb could lower the corresponding catalytic activity. These findings help to support future applications of ATO/Pt-based materials as possible cathodes for proton exchange membrane fuel cell applications with enhanced durability under practical applications.
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Fysikvej, 2800 Kongens Lyngby, Denmark.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.affiliation: SINTEF Materials and Chemistry, NO0-7465 Trondheim, Norway.
authors.forename: Luis César
authors.initials: LC
authors.lastname: Colmenares Rausseo
authors.affiliation: QuantumWise A/S, Fruebjergvej 3, Postbox 4, 2100 Copenhagen, Denmark.
authors.forename: Umberto
authors.initials: U
authors.lastname: Martinez
authors.affiliation: SINTEF Materials and Chemistry, NO0-7465 Trondheim, Norway.
authors.forename: Paul Inge
authors.initials: PI
authors.lastname: Dahl
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Fysikvej, 2800 Kongens Lyngby, Denmark.
authors.forename: Juan Maria
authors.initials: JM
authors.lastname: García Lastra
authors.affiliation: SINTEF Materials and Chemistry, NO0-7465 Trondheim, Norway.
authors.forename: Per Erik
authors.initials: PE
authors.lastname: Vullum
authors.affiliation: SINTEF Materials and Chemistry, NO0-7465 Trondheim, Norway.
authors.forename: Ingeborg-Helene
authors.initials: IH
authors.lastname: Svenum
authors.affiliation: Department of Energy Conversion and Storage, Technical University of Denmark , Fysikvej, 2800 Kongens Lyngby, Denmark.
authors.forename: Tejs
authors.initials: T
authors.lastname: Vegge
keywords: catalyst; electronic transport; fuel cell; interface; segregation