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N. Barrabés-Rabanal, S. Pollitt, G. Rupprechter:
"Stability and reactivity of Au₃₈ (SR)₂₄/Ce0₂ nanoclusters catalyst in oxidation reactions by operando XAFS studies";
Poster: OperandoVI - 6th International Congress on Operando Spectroscopy, Estepona, Malaga; 15.04.2018 - 19.04.2018; in: "OperandoVI - 6th International Congress on Operando Spectroscopy", (2018), S. 134.

Thiolate protected Au nanocluster supported on oxides have been proven to be active in several catalytic reactions with higher yields in comparison with the nanoparticles pair ones. Aun(SR)m/MO x represents an important model catalyst for structure-activity correlation study due to its well-defined atomically precise structures dealing to truly homogenous surfaces. Although the structure stability and interaction with the oxide support material under reaction conditions has been not studied that represents the
key information for understanding their catalytic behavior. Our previous observation of Au3/Mx0y under oxidative pretreatments by EXAFS at Au L3-edge showed different interactions depending on the oxide materials and higher stability in the case of Ce0 . 1 XANES S K-edge revealed the ligand-support
interaction upon supporting with the presence of S species at high oxidation state. This represents the first evidence for the distribution of the thiolate ligand between nanocluster and support. Further conversion of the S species was observed upon thermal pre-treatment and during reaction (cyclohexane oxidation in liquid phase), which could affect the active sites on the support surface and charge transfer between support and nanocluster. The continuous evolution of S species, rather than complete removal from support material, gives rise to complicate selectivity towards oxidation products and explained previous selectivity changes depending on the level of ligand removal in several reactions