RETRACTED: Surface-engineered Cu-substituted CeO2 Nanocatalysts for Low-temperature CO Oxidation

ChemRxiv

Abstract

Retracted at the authors' request because recent experimental data calls into question the preprint’s conclusions. The precise engineering of active sites on heterogeneous catalysts relies on a comprehensive and in-depth understanding of surface structures. Cu-substituted CeO2 catalysts have emerged as promising alternatives to noble metal-based catalysts for CO oxidation. Recent studies have demonstrated correlations between the Cu substitution amount and catalytic activity, however, the underlying atomistic mechanism governing this behavior remains unclear. Herein, we evaluated a series of Cu-substituted CeO2 rod-shaped nanocatalysts, aiming to rationally design a catalyst with a high density of active sites on the surface. The combined spectroscopic investigations, complemented by advanced electron microscopy analysis, revealed a complex interplay between electronic charge carriers localized on both Cu, Ce sites, and the corresponding abundance of oxygen vacancies. Specifically, 10% Cu substitution leads to the highest surface reactivity. First principles Monte Carlo simulations further confirmed the highest surface-available Cu concentration of 10%. Consequently, 10% Cu-substituted CeO2 exhibits superior catalytic performance for low-temperature CO oxidation. The existence of Cu+ species and Cu(0) nanoislands promotes the CO adsorption, while dispersed Cu2+ ions induce lattice distortion and charge imbalance, thus facilitating lattice oxygen mobility. This study reveals novel insights into the influence of heteroatom substitution on catalytically active sites for CeO2-based catalysts.

Authors 18

1. Xiaochao Wu Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University

2. Gunjana Yadav Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University

3. Maria Meledina

   Thermo Fisher Scientific (Netherlands)

   Affiliation as printed

   Thermo Fisher Scientific (Netherlands)

4. Dileep Krishnan

   Thermo Fisher Scientific (Netherlands)

   Affiliation as printed

   Thermo Fisher Scientific (Netherlands)

5. Maarten Wirix

   Thermo Fisher Scientific (Netherlands)

   Affiliation as printed

   Thermo Fisher Scientific (Netherlands)

6. Daen Jannis

   University of Antwerp

   Affiliation as printed

   University of Antwerp

7. C. Ozsoy-Keskinbora

   Thermo Fisher Scientific (Netherlands)

   Affiliation as printed

   Thermo Fisher Scientific (Netherlands)

8. Ahed Abouserie Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University

9. Daniel Röhrens Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH

10. Michael Noyong Aachen

    RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University

11. Felix Ott Aachen

    RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University

12. Fabian Fink Aachen

    RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University

13. Sonja Herres‐Pawlis Aachen

    RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University

14. Regina Palkovits Aachen

    RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University

15. Paolo Longo

    Thermo Fisher Scientific (Netherlands)

    Affiliation as printed

    Thermo Fisher Scientific (Netherlands)

16. David N. Mueller

    Forschungszentrum Jülich

    Affiliation as printed

    Forschungszentrum Jülich

17. Abhishek Khetan Aachen

    RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University

18. Ulrich Simon Aachen

    RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University