Lattice-strain control of the activity in dealloyed core-shell fuel cell catalysts.
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.
Strasser
Peter
P
The Electrochemical Energy, Catalysis, and Materials Science Laboratory, Department of Chemistry, Chemical Engineering Division, Technical University Berlin, 10623 Berlin, Germany. pstrasser@tu-berlin.de
Koh
Shirlaine
S
Anniyev
Toyli
T
Greeley
Jeff
J
More
Karren
K
Yu
Chengfei
C
Liu
Zengcai
Z
Kaya
Sarp
S
Nordlund
Dennis
D
Ogasawara
Hirohito
H
Toney
Michael F
MF
Nilsson
Anders
A
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
D010984:Platinum; D003300:Copper; D010100:Oxygen