Author/Authors :
Ochal، نويسنده , , Piotr and Gomez de la Fuente، نويسنده , , Jose Luis and Tsypkin، نويسنده , , Mikhail and Seland، نويسنده , , Frode and Sunde، نويسنده , , Svein and Muthuswamy، نويسنده , , Navaneethan and Rّnning، نويسنده , , Magnus and Chen، نويسنده , , De and Garcia، نويسنده , , Sergio and Alayoglu، نويسنده , , Selim and Eichhorn، نويسنده , , Bryan، نويسنده ,
Abstract :
The paper reports an application of CO stripping-voltammetry as a diagnostic tool for the determination of surface composition of various PtRu nanoparticles (NPs). A series of electrochemical experiments on different systems, including monometallic Pt and Ru, a commercially available PtRu alloy, Ru@Pt (Ru NPs covered by a Pt shell), and their physical mixtures verified that the surface of the Ru@Pt particles does not contain significant amounts of ruthenium. A large cathodic shift (200 mV) of the main CO stripping peak of the Ru@Pt with respect to that of Pt was observed, consistent with what has been found at other catalysts with a Pt skin but of a different architecture. An additional small separate stripping peak at a potential corresponding to the oxidation of adsorbed CO at Pt/C is interpreted as being due to either separate Pt particles in the catalyst or thick Pt shells at a minor fraction of the Ru@Pt particles. Since the method probes the whole sample it will be useful for assessment of catalyst homogeneity.
Keywords :
CO electrooxidation , bifunctional , ligand , Electrocatalyst , bimetallic
