Platinum- and gold-coated iron, cobalt, nickel and lead particles deposited on glassy carbon electrode substrates have been tested for oxygen reduction in acid solutions. Fe, Co, Ni or Pb layers were electro-deposited onto glassy carbon and subsequently immersed into chloroplatinic or chlorolaurate acid solutions where the spontaneous surface exchange of M (M - Fe, Co, Ni or Pb) for Pt or Au resulted in Pt(M)/ GC and Au(M)/CC electrodes. The bimetallic deposits displayed typical Pt and Au surface electrochemistry indicating the formation of a continuous noble metal shell over a non-precious metal-containing core. The activity of the Pt(M)/GC and Au(M)/GC towards oxygen reduction in acid was studied by voltammetry at a rotating disc electrode and compared to that of bulk Pt or Au and Pt(Cu)/GC or Au(Cu)/GC (reported previously). Interpretation of the results is based on the metal M electronic effect on the Pt or Au shell. (c) 2008 Elsevier B.V. All rights reserved.