title: Lattice-strain control of the activity in dealloyed core-shell fuel cell catalysts.
abstract: Electrocatalysis will play a key role in future energy conversion and storage technologies, such as water electrolysers, fuel cells and metal-air batteries. Molecular interactions between chemical reactants and the catalytic surface control the activity and efficiency, and hence need to be optimized; however, generalized experimental strategies to do so are scarce. Here we show how lattice strain can be used experimentally to tune the catalytic activity of dealloyed bimetallic nanoparticles for the oxygen-reduction reaction, a key barrier to the application of fuel cells and metal-air batteries. We demonstrate the core-shell structure of the catalyst and clarify the mechanistic origin of its activity. The platinum-rich shell exhibits compressive strain, which results in a shift of the electronic band structure of platinum and weakening chemisorption of oxygenated species. We combine synthesis, measurements and an understanding of strain from theory to generate a reactivity-strain relationship that provides guidelines for tuning electrocatalytic activity.
authors.affiliation: The Electrochemical Energy, Catalysis, and Materials Science Laboratory, Department of Chemistry, Chemical Engineering Division, Technical University Berlin, 10623 Berlin, Germany. pstrasser@tu-berlin.de
authors.forename: Peter
authors.initials: P
authors.lastname: Strasser
authors.forename: Shirlaine
authors.initials: S
authors.lastname: Koh
authors.forename: Toyli
authors.initials: T
authors.lastname: Anniyev
authors.forename: Jeff
authors.initials: J
authors.lastname: Greeley
authors.forename: Karren
authors.initials: K
authors.lastname: More
authors.forename: Chengfei
authors.initials: C
authors.lastname: Yu
authors.forename: Zengcai
authors.initials: Z
authors.lastname: Liu
authors.forename: Sarp
authors.initials: S
authors.lastname: Kaya
authors.forename: Dennis
authors.initials: D
authors.lastname: Nordlund
authors.forename: Hirohito
authors.initials: H
authors.lastname: Ogasawara
authors.forename: Michael F
authors.initials: MF
authors.lastname: Toney
authors.forename: Anders
authors.initials: A
authors.lastname: Nilsson
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry* / Q000378:metabolism; D010984:Platinum / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D010984:Platinum; D003300:Copper; D010100:Oxygen