Ultra-Thin Platinum Deposits by Surface-Limited Redox Replacement of Tellurium
Fatima Haidar,
Mathieu Maas,
Andrea Piarristeguy,
Annie Pradel,
Sara Cavaliere,
Marie-Christine Record
Affiliations
Fatima Haidar
Institute Charles Gerhardt of Montpellier, UMR CNRS 5253, Chalcogenide Materials and Glasses, University of Montpellier, F-34095 Montpellier CEDEX 5, France
Mathieu Maas
Institute Charles Gerhardt of Montpellier, UMR CNRS 5253, Chalcogenide Materials and Glasses, University of Montpellier, F-34095 Montpellier CEDEX 5, France
Andrea Piarristeguy
Institute Charles Gerhardt of Montpellier, UMR CNRS 5253, Chalcogenide Materials and Glasses, University of Montpellier, F-34095 Montpellier CEDEX 5, France
Annie Pradel
Institute Charles Gerhardt of Montpellier, UMR CNRS 5253, Chalcogenide Materials and Glasses, University of Montpellier, F-34095 Montpellier CEDEX 5, France
Sara Cavaliere
Institute Charles Gerhardt of Montpellier, UMR CNRS 5253, Aggregates Interfaces and Materials for Energy, University of Montpellier, F-34095 Montpellier CEDEX 5, France
Marie-Christine Record
Institute Charles Gerhardt of Montpellier, UMR CNRS 5253, Chalcogenide Materials and Glasses, University of Montpellier, F-34095 Montpellier CEDEX 5, France
Platinum is the most employed electrocatalyst for the reactions taking place in energy converters, such as the oxygen reduction reaction in proton exchange membrane fuel cells, despite being a very low abundant element in the earth’s crust and thus extremely expensive. The search for more active electrocatalysts with ultra-low Pt loading is thus a very active field of investigation. Here, surface-limited redox replacement (SLRR) that utilizes the monolayer-limited nature of underpotential deposition (UPD) was used to prepare ultrathin deposits of Pt, using Te as sacrificial metal. Cyclic voltammetry and anodic potentiodynamic scanning experiments have been performed to determine the optimal deposition conditions. Physicochemical and electrochemical characterization of the deposited Pt was carried out. The deposit comprises a series of contiguous Pt islands that form along the grain interfaces of the Au substrate. The electrochemical surface area (ECSA) of the Pt deposit obtained after 5 replacements, estimated to be 18 m2/g, is in agreement with the ECSA of extended surface catalysts on flat surfaces.
