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Electronic metal–support interactions (EMSI) describe the electron flow between metal sites and a metal oxide support. It is generally used to follow the mechanism of redox reactions. In this study of CuO‐CeO2 redox, an additional flow of electrons from metallic Cu to surface carbon species is observed via a combination of operando X‐ray absorption spectroscopy, synchrotron X‐ray powder diffraction, near ambient pressure near edge X‐ray absorption fine structure spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy. An electronic metal–support–carbon interaction (EMSCI) is proposed to explain the reaction pathway of CO oxidation. The EMSCI provides a complete picture of the mass and electron flow, which will help predict and improve the catalytic performance in the selective activation of CO2, carbonate, or carbonyl species in C1 chemistry. [ABSTRACT FROM AUTHOR]

The current interest in research and development of solid electrolytes for battery systems dictates a necessity to evaluate their electrochemical stability in a wide potential range. It is supposed that the stability and properties of the interface formed between the electrode and solid electrolyte at the applied potential (the analog of solid electrolyte interphase (SEI) in liquid electrolytes) are of great importance for the battery operation. While the electrochemical techniques can provide the knowledge of a stability window of the solid electrolyte, a direct method, which helps to trace chemical changes, is still missing, due to the difficulty to reach the interface between the solid electrolyte and thick electrode material. In this paper, we propose to use two-layer graphene transferred directly on the solid electrolyte as the electrode transparent for photoelectrons. Such an electrode is thin enough to probe the interface by X-ray photoelectron spectroscopy to trace the occurring chemical changes. To demonstrate this possibility, we have investigated the electrochemical reduction of Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass-ceramic electrolyte by in situ XPS. [ABSTRACT FROM AUTHOR]

Iridium-based materials are among the most active and stable electrocatalysts for the oxygen evolution reaction. Amorphous iridium oxide structures are found to be more active than their crystalline counterparts. Herein, we combine synchrotron-based X-ray photoemission and absorption spectroscopies with theoretical calculations to investigate the electronic structure of Ir metal, rutile-type IrO2, and an amorphous IrOx. Theory and experiment show that while the Ir 4f line shape of Ir metal is well described by a simple Doniach-Šunjić function, the peculiar line shape of rutile-type IrO2 requires the addition of a shake-up satellite 1 eV above the main line. In the catalytically more active amorphous IrOx, we find that additional intensity appears in the Ir 4f spectrum at higher binding energy when compared with rutile-type IrO2 along with a pre-edge feature in the O K-edge. We identify these additional features as electronic defects in the anionic and cationic frameworks, namely, formally OI− and IrIII, which may explain the increased activity of amorphous IrOx electrocatalysts. We corroborate our findings by in situ X-ray diffraction as well as in situ X-ray photoemission and absorption spectroscopies. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]