• Berretti, Enrico
• Lepore, Giovanni Orazio
• Benedetto, Francesco Di
• Dellaquila, Vincenzo
• Innocenti, Massimo
• Lavacchi, Alessandro
• Dacapito, Francesco
• Giaccherini, Andrea
• Vizza, Francesco
• Montegrossi, Giordano

Abstract

<jats:title>Abstract</jats:title><jats:p>In this article, we present an <jats:italic>in-situ</jats:italic> and <jats:italic>operando</jats:italic> time-resolved X-ray Absorption Spectroscopy (XAS) technique which exploits a combination of Grazing Incidence XAS (GIXAS) and Fixed Energy X-ray Absorption Voltammetry (FEXRAV), the Grazing Incidence FEXRAV (GI-FEXRAV). A case-study is also outlined. Palladium ultra-low loadings were deposited above Au polycrystalline iso-oriented substrates adopting three different deposition methods: surface-controlled electrochemical methods, direct electrodeposition, and physical vapour deposition (PVD). These catalytical surfaces were prepared for the investigation by GI-FEXRAV of the Pd oxidation/dissolution phenomenon that could occur when the metal is used in the anodic compartment of Direct Alcohol Fuel Cells (DAFCs) or in electrochemical reformers. Moreover, we report a robust, low cost and versatile procedure to obtain wide and flat iso-oriented gold substrates that can mimic monocrystalline gold (1 1 1) in the electrochemical response. The use of GI-FEXRAV for the <jats:italic>operando</jats:italic> characterization of the catalysts, in conjunction with the designed experimental cell and our flexible Au-based electrochemical substrates show an invaluable potential in the <jats:italic>operando</jats:italic> study of fundamental phenomena in heterogeneous electrocatalysis model systems and, due to its versatility, paves the way to further studies on a wide selection of electrochemical systems.</jats:p>

Topics

• impedance spectroscopy
• surface
• gold
• physical vapor deposition
• electrodeposition
• alcohol
• x-ray absorption spectroscopy
• palladium
• voltammetry