Indirect nuclear spin-spin J-coupling measurements have been carried out on a conducting, carbon-supported 8.8 nm platinum electrocatalyst by using Pt-195 NMR. The J-coupling values show a marked variation across the spectrum. These J-coupling values were then transformed into the corresponding s-like Fermi level local density of states D-s(E-r, x), where x is the distance from the particle surface, revealing a spatially resolved oscillatory decay in D-s(E-f) which is responsible for the line broadening of the bulk peak in the Pt-195 NMR spectrum. (C) 2002 Elsevier Science B.V. All rights reserved.