Lattice-strain control of the activity in dealloyed core-shell fuel cell catalysts

Nat Chem. 2010 Jun;2(6):454-60. doi: 10.1038/nchem.623. Epub 2010 Apr 25.

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Catalysis
  • Copper / chemistry*
  • Electrochemistry*
  • Metal Nanoparticles / chemistry*
  • Oxygen / chemistry*
  • Oxygen / metabolism
  • Platinum / chemistry*
  • Surface Properties

Substances

  • Platinum
  • Copper
  • Oxygen