Effect of Different In2O3(111) Surface Terminations on CO2 Adsorption

S. M. Gericke, M. M. Kauppinen, M. Wagner, M. Riva, G. Franceschi, A. Posada-Borbón, L. Rämisch, S. Pfaff, E. Rheinfrank, A. M. Imre, A. B. Preobrajenski, S. Appelfeller, S. Blomberg, L. R. Merte, J. Zetterberg, U. Diebold, H. Grönbeck, E. Lundgren

Division of Combustion Physics, Lund University, 22100 Lund, Sweden
Department of Physics and Competence Centre for Catalysis, Chalmers University of Technology, 41296 Göteborg, Sweden
Institut für Angewandte Physik, TU Wien, 1040 Wien, Austria
MAX IV Laboratory, Lund University, 22100 Lund, Sweden
Department of Chemical Engineering, Lund University, 22100 Lund, Sweden Department of Materials Science and Applied Mathematics, Malmö University, 20506 Malmö, Sweden
Division of Synchrotron Radiation Research, Lund University, 22100 Lund, Sweden

ACS Appl. Mater. Interfaces 15 (2023) 45367-45377

In2O3-based catalysts have shown high activity and selectivity for CO2 hydrogenation to methanol; however, the origin of the high performance of In2O3 is still unclear. To elucidate the initial steps of CO2 hydrogenation over In2O3, we have combined X-ray photoelectron spectroscopy and density functional theory calculations to study the adsorption of CO2 on the In2O3(111) crystalline surface with different terminations, namely, the stoichiometric, reduced, and hydroxylated surface. The combined approach confirms that the reduction of the surface results in the formation of In adatoms and that water dissociates on the surface at room temperature. A comparison of the experimental spectra and the computed core-level shifts (using methanol and formic acid as benchmark molecules) suggests that CO2 adsorbs as a carbonate on all three surface terminations. We find that the adsorption of CO2 is hindered by hydroxyl groups on the hydroxylated surface.

Corresponding author: Sabrina M. Gericke. Reprints also available from Margareta Wagner (wagner at iap_tuwien_ac_at).

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