Observation of surface structural changes of Pt octahedron nanoparticles and its effect in electrocatalysis oxidation of methanol

The Pt octahedron nanoparticles closed by 8 {111} facets are synthesized as catalyst for methanol oxidation. The catalytic activity of the Pt octahedron nanoparticles is enhanced significantly after applying a number of potential cycles. Such enhancement is due to the formation of the defect and step sites introduced by the potential cycles, which is directly confirmed by transmission electron micrograph. Accumulation of the defect and step sites result in a formation of Pt(100) terraces, arising from more potential cycles. The poisoning of Pt(100) terraces leads to a rapid decay in the long-term performance. (C) 2009 Elsevier B.V. All rights reserved.