Pd/Co3O4(111) Interface Formation

Kastenmeier M, Fusek L, Mohamed F, Schuschke C, Ronovský M, Skála T, Farnesi Camellone M, Tsud N, Johánek V, Fabris S, Libuda J, Piccinin S, Lykhach Y, Mysliveček J, Brummel O (2023)

Publication Type: Journal article

Publication year: 2023

Journal

DOI: 10.1021/acs.jpcc.3c00261

Abstract

The formation of the metal-oxide interface in the Pd/Co3O4(111) model catalyst was investigated by means of density functional theory (DFT), synchrotron radiation photoelectron spectroscopy (SRPES), and scanning tunneling microscopy (STM). The electronic metal-support interaction results in a substantial charge transfer at the interface yielding atomically dispersed Pd²⁺ species and partially oxidized Pd^δ+ aggregates coupled with a partial reduction of Co3O4(111). Atomically dispersed Pd²⁺ species at the fcc site on the Co3O4(111) surface were found to be the most energetically favorable configuration. In comparison to the dispersed Pd²⁺ species, the formation of Pd dimers, trimers, and tetramers was found to be less favorable. The analysis of the Bader charges revealed a substantial net positive charge on Pd atoms in dimers, trimers, and tetramers which is consistent with the formation of partially oxidized Pd^δ+ aggregates detected by SRPES. The analysis of the charge distribution in Co3O4(111) revealed a partial reduction of Co³⁺ to Co²⁺ cations in the first and second Co layers. According to DFT, Pd^δ+ aggregates are prone to oxidation to PdO in the presence of O2 and H2O. The partially oxidized Pd^δ+ and Pd4Ox aggregates form 1 to 2 monolayer thick clusters which serve as nuclei for the growth of metallic Pd⁰ nanoparticles. At high Pd coverage, Pd nanoparticles coalesce resulting in the growth of two-dimensional islands that densely cover the Co3O4(111) substrate.

Authors with CRIS profile

Involved external institutions

University of Khartoum / جامعة الخرطوم Sudan (SD) Univerzita Karlova v Praze / Charles University in Prague Czech Republic (CZ) IOM - Istituto Officina dei Materiali Italy (IT)

How to cite

APA:

Kastenmeier, M., Fusek, L., Mohamed, F., Schuschke, C., Ronovský, M., Skála, T.,... Brummel, O. (2023). Pd/Co3O4(111) Interface Formation. Journal of Physical Chemistry C. https://doi.org/10.1021/acs.jpcc.3c00261

MLA:

Kastenmeier, Maximilian, et al. "Pd/Co3O4(111) Interface Formation." Journal of Physical Chemistry C (2023).

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