Journal Article

PUBDB-2020-04372

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png In situ probing of Pt/TiO$_{2}$ activity in low-temperature ammonia oxidation

Kibis, L. S.Extern* ; Svintsitskiy, D.Extern* ; Stadnichenko, A. I.Extern* ; Slavinskaya, E. M. ; Romanenko, A. ; Fedorova, E. A. ; Stonkus, O. A. ; Svetlichnyi, V. ; Fakhrutdinova, E. D. ; Vorokhta, M. ; Šmíd, B. ; Doronkin, D. E.Extern* ; Marchuk, V.Extern* ; Grunwaldt, J.-D.Extern* ; Boronin, A. I. (Corresponding author)

2020
RSC Publ. London

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Please use a persistent id in citations: doi:10.1039/D0CY01533D  doi:10.3204/PUBDB-2020-04372

Abstract: The improvement of the low-temperature activity of the supported platinum catalysts in selective ammonia oxidation to nitrogen is still a challenging task. The recent developments in in situ/operando characterization techniques allows to bring new insight into the properties of the systems in correlation with their catalytic activity. In this work, near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and operando X-ray absorption spectroscopy (XAS) techniques were applied to study Pt/TiO$_{2}$ catalysts in ammonia oxidation (NH$_{3}$ + O$_{2}$ reaction). Several synthesis methods were used to obtain samples with different size of Pt particles, oxidation state of Pt, and morphology of the support. Metal platinum particles on titania prepared by pulsed laser ablation in liquids exhibited the highest activity at lower temperatures with the temperature of 50% conversion of NH$_{3}$ being 150 °C. The low-temperature activity of the catalysts synthesized by impregnation can be improved by the reductive pretreatment. NAP-XPS and operando XANES data do not show formation of PtO$_{x}$ surface layers or PtO/PtO$_{2}$ oxides during NH$_{3}$ + O$_{2}$ reaction. Despite the differences in the oxidation state of platinum in the as-prepared catalysts, their treatment in the reaction mixture results in the formation of metallic platinum particles, which can serve as centers for stabilization of the adsorbed oxygen species. Stabilization of the bulk platinum oxide structures in the Pt/TiO$_{2}$ catalysts seems to be less favorable due to the metal–support interaction.

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Contributing Institute(s):

1. DOOR-User (DOOR ; HAS-User)

Research Program(s):

1. 6G3 - PETRA III (POF3-622) (POF3-622)
2. FS-Proposal: I-20181000 (I-20181000) (I-20181000)

Experiment(s):

1. PETRA Beamline P65 (PETRA III)

Appears in the scientific report 2020

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Database coverage:
; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF >= 5 ; JCR ; National-Konsortium ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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