Methanol oxidation at platinized lead coatings prepared by a two-step electrodeposition–electroless deposition process on glassy carbon and platinum substrates

Platinized lead deposits, Pt(Pb), have been formed on glassy carbon (GC) and platinum electrodes by a two-step process, whereby a controlled amount of Pb was electrodeposited onto the substrates and was subsequently coated with a thin Pt layer upon immersion of the Pb/GC or Pb/Pt electrodes into a chloroplatinic acid solution. The spontaneous surface replacement of Pb by Pt resulted in Pt(Pb)/GC or Pt(Pb)/Pt electrodes which consisted of dispersed Pt(Pb) particles and displayed typical Pt surface electrochemistry in deaerated acid solutions. When tested as methanol oxidation anodes, these electrodes exhibited enhanced electrocatalytic activity both during voltammetric and constant potential experiments. This behaviour is attributed to an electronic effect of the underlying Pb onto the Pt surface layer.