Brummel O, Lykhach Y, Vorokhta M, Smid B, Stumm C, Faisal F, Skala T, Tsud N, Neitzel A, Beranova K, Prince KC, Matolin V, Libuda J (2019)
Publication Type: Journal article
Publication year: 2019
Book Volume: 123
Pages Range: 8746-8758
Journal Issue: 14
Achieving high stability of supported noble metal nanoparticles with respect to sintering is one of the major challenges in electrocatalysis. In this study, we explored the role of metal-support interaction in stabilizing the morphology of a well-defined model electrode consisting of Pt nanoparticles supported on well-ordered Co 3 O 4 (111) films on Ir(100). We employed X-ray photoelectron spectroscopy coupled with an electrochemical cell to analyze changes in the oxidation states of both the supported Pt nanoparticles and Co 3 O 4 (111) support as a function of electrode potential. We found that immersion into the aqueous electrolyte at pH 10 (phosphate buffer) has no effect on the integrity and chemical composition of the Co 3 O 4 (111) film in a potential window between 0.5 and 1.4 V RHE . At lower potentials, reduction of the Co 3 O 4 (111) to Co(OH) 2 and metallic Co is accompanied by rapid dissolution of the film. In the presence of supported Pt particles, metal-support interaction gives rise to the formation of partially oxidized Pt δ+ species at the metal/oxide interface. Under electrochemical conditions, these species are readily oxidized yielding platinum oxide at the Pt/Co 3 O 4 (111) interface at potentials as low as 0.5 V RHE . The appearance of interfacial platinum oxide is accompanied by the formation of surface and bulk platinum oxides at potentials above 1.0 and 1.1 V RHE , respectively. While the formation and decomposition of surface and bulk platinum oxides depend on the electrode potential, the interface platinum oxide is stable between 0.5 and 1.4 V RHE . We propose that the high stability of supported Pt nanoparticles with respect to sintering is associated with the presence of platinum interface oxide stabilized by the metal-support interaction. ©
APA:
Brummel, O., Lykhach, Y., Vorokhta, M., Smid, B., Stumm, C., Faisal, F.,... Libuda, J. (2019). Redox Behavior of Pt/Co3O4(111) Model Electrocatalyst Studied by X-ray Photoelectron Spectroscopy Coupled with an Electrochemical Cell. Journal of Physical Chemistry C, 123(14), 8746-8758. https://doi.org/10.1021/acs.jpcc.8b08890
MLA:
Brummel, Olaf, et al. "Redox Behavior of Pt/Co3O4(111) Model Electrocatalyst Studied by X-ray Photoelectron Spectroscopy Coupled with an Electrochemical Cell." Journal of Physical Chemistry C 123.14 (2019): 8746-8758.
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