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  Ziemba, M.; Weyel, J.; Zeller, P.; Welzenbach, J.; Efimenko, A.; Hävecker, M.; Hess, C.: Importance of Metal-Support Interactions for CO₂ Hydrogenation: An Operando Near-Ambient Pressure X-ray Photoelectron Spectroscopy Study on Gold-Loaded In₂O₃ and CeO₂ Catalysts. The Journal of Physical Chemistry Letters 15 (2024), p. 4928-4932

10.1021/acs.jpclett.4c00653
Open Access Version (available 01.04.2025)

Abstract:
Metal–support interactions, which are essential for the design of supported metal catalysts, used, e.g., for CO2 activation, are still only partially understood. In this study of gold-loaded In2O3 and CeO2 catalysts during CO2 hydrogenation using near-ambient pressure X-ray photoelectron spectroscopy, supported by near edge X-ray absorption fine structure, we demonstrate that the role of the noble metal strongly depends upon the choice of the support material. Temperature-dependent analyses of X-ray photoelectron spectra under reaction conditions reveal that gold is reduced on CeO2, enabling direct H2 activation, but oxidized on In2O3, leading to decreased activity of Au/In2O3 compared to bare In2O3. At elevated temperatures, the catalytic activity of the In2O3 catalysts strongly increases as a result of facilitated CO2 and (In2O3-based) H2 activation, while the catalytic activity of Au/CeO2 is limited by reoxidation by CO2. Our results underline the importance of operando studies for understanding metal–support interactions to enable a rational support selection in the future.