title: Diffusion on a nanoparticle surface as revealed by electrochemical NMR.
abstract: Surface diffusion of chemisorbed CO (from MeOH electrochemisorption) on pure and Ru-modified nanoscale Pt electrocatalyst surfaces has been investigated by solid-state electrochemical NMR (EC-NMR) in the presence of supporting electrolyte. Temperature-dependent nuclear spin-spin and spin-lattice relaxation measurements enable the diffusion activation energy, E, to be deduced. It is shown that the activation energy E correlates with the steady state current for MeOH electro-oxidation. A simple two-dimensional collision theory model is proposed to explain this intriguing observation, which may provide new mechanistic insights into the promotion of CO-tolerance in Pt/Ru fuel cell catalysts.
authors.affiliation: Department of Chemistry, Georgetown University, Washington, DC 20057, USA.
authors.forename: Y Y
authors.initials: YY
authors.lastname: Tong
authors.forename: E
authors.initials: E
authors.lastname: Oldfield
authors.forename: A
authors.initials: A
authors.lastname: Wieckowski