Volkmar Koller^1,2, Pablo G. Lustemberg^3*, Alexander Spriewald-Luciano^1,2, Sabrina M. Gericke⁴, Alfred Larsson⁵, Christian Sack^1,2, Alexei Preobrajenski⁶, Edvin Lundgren⁵, M. Veronica Ganduglia-Pirovano³, Herbert Over^1,2

1 Physical Chemistry Department, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 17, 35392 Giessen, Germany

2 Center for Materials Research, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 16, 35392 Giessen, Germany

3 Institute of Catalysis and Petrochemistry, ICP, Spanish National Research Council, CSIC, 28049 Madrid, Spain

4 Combustion Physics, Lund University, Box 118, 22100 Lund, Sweden

5 Synchrotron Radiation Research, Lund University, Box 118, 22100 Lund, Sweden

6 MAX IV Laboratory, Lund University, Box 118, 22100 Lund, Sweden

* Corresponding authors emails: p.lustemberg@csic.es

DOI10.24435/materialscloud:dq-1c [version v1]

Publication date: Sep 19, 2023

How to cite this record

Volkmar Koller, Pablo G. Lustemberg, Alexander Spriewald-Luciano, Sabrina M. Gericke, Alfred Larsson, Christian Sack, Alexei Preobrajenski, Edvin Lundgren, M. Veronica Ganduglia-Pirovano, Herbert Over, Critical step in the HCl oxidation reaction over single-crystalline CeO2−x(111): Peroxo-induced site change of strongly adsorbed surface chlorine, Materials Cloud Archive 2023.143 (2023), https://doi.org/10.24435/materialscloud:dq-1c

Description

The catalytic oxidation of HCl by molecular oxygen (Deacon process) over ceria allows the recovery of molecular chlorine from omnipresent HCl waste produced in various industrial processes. In previous density functional theory (DFT) model calculations by Amrute et al. [J. Catal. 2012, 286, 287–297.], it was proposed that the most critical reaction step in this process is the displacement of tightly bound chlorine at a vacant oxygen position on the CeO2(111) surface (Clvac) toward a less strongly bound cerium on-top (Cltop) position. This step is highly endothermic by more than 2 eV. On the basis of a dedicated model study, namely the re-oxidation of a chlorinated single crystalline Clvac-CeO2−x(111)-(√3 × √3)R30° surface structure, we provide in-situ synchrotron-based spectroscopic data (high-resolution core level spectroscopy (HRCLS) and X-ray adsorption near edge structure (XANES)) for this oxygen-induced de-chlorination process. Combined with theoretical evidence from DFT calculations, the Clvac → Cltop displacement reaction is predicted to be induced by an adsorbed peroxo species (O22-), making the displacement step concerted and exothermic by only 0.6 eV with an activation barrier of only 1.04 eV. The peroxo species is shown to be important for the re-oxidation of Clvac-CeO2−x(111) and is considered essential for understanding the function of ceria in oxidation catalysis.

Materials Cloud sections using this data

Files

File name	Size	Description
README.txt MD5md5:cd0c8c4862421aba19389989f3617e3a	2.9 KiB	Contains the description of the data uploaded to the repository.
Figure7a.zip MD5md5:eedf9de40726f4cf7a8f1ce1a3d74baf	2.5 MiB	O2-activation at 3Clvac- Ce3O5(111)-(3x3)
Figure7b.zip MD5md5:6b610aa2562b395eda076651b0daedfa	866.2 KiB	Adsorbed peroxo(O2ads)and atomic oxygen on top of Ce atom (Otop).
Figure8.zip MD5md5:9f10b6f937957a45939adcb4847c8859	4.6 MiB	Re-oxidation process of 3Clvac-Ce3O5(111)-(3 x 3).
Figure9.zip MD5md5:2de18506e8f0e4041d4c6c9d0f095bf1	5.9 MiB	De-chlorination process of 3Clvac-Ce3O5(111)-(3 x 3)
FigureS12.zip MD5md5:933108113c3ee54ba5d090a9960c6c62	11.4 MiB	States corresponding to the diffusion from a VSSS to VSS to VS vacancy in CeO2(111), Ce3O5(111) and 3Clvac/Ce3O5(111)
FigureS13.zip MD5md5:bb2726f23121d38d9950c4612130f80a	1.5 MiB	O2 specie adsorbed as a peroxo o superoxo on 3Clvac/Ce3O5.
FigureS14.zip MD5md5:2568f41b37f06bfe7bbc08e3eab7f79f	50.3 KiB	Atomic coordinates of the de-chlorination process from two adsorbed O2 species and three Cl adsorbed on oxygen vacancies
FigureS15.zip MD5md5:088759d9f5781cf6cf1a4248830f46c9	1.5 MiB	Initial state (IS) and final state (FS) connecting two peroxo states.
FigureS17.zip MD5md5:0098d52cb6eacd4c6176cd9cc9e65b7e	5.4 MiB	States corresponding to Cl atoms at 1/3 ML, 2/3 ML, and 1 ML in the (√3 × √3)R30° with 3 oxygen vacancies.

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External references

Keywords

Deacon process reduced ceria peroxo surface species displacement of strongly adsorbed chlorine oxygen-induced de-chlorination process