Journal Article

PUBDB-2019-03552

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Impact of Preparation Method and Hydrothermal Aging on Particle Size Distribution of $Pt/γ-Al_{2}O_{3}$ and Its Performance in CO and NO Oxidation

Ogel, E.Extern* ; Casapu, M.Extern* ; Doronkin, D. E. ; Popescu, R. ; Störmer, H. ; Mechler, C. ; Marzun, G. ; Barcikowski, S. ; Türk, M. ; Grunwaldt, J.-D. (Corresponding author)Extern*

2019
Soc.10927 Washington, DC

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Please use a persistent id in citations: doi:10.1021/acs.jpcc.8b11065  doi:10.3204/PUBDB-2019-03552

Abstract: The influence of the preparation method and the corresponding particle size distribution on hydrothermal deactivation behavior at 600-800°C and its performance during CO/NO oxida-tion was systematically investigated for a series of Pt/Al2O3 catalysts. Representative conven-tional (incipient wetness impregnation) and advanced preparation methods (flame spray pyrol-ysis, supercritical fluid reactive deposition and laser ablation in liquid) were selected, which generated samples containing narrow and homogeneous but also heterogeneous particle size distributions. Basic characterization was conducted by inductively coupled plasma-optical emission spectrometry, N2 physisorption and X-ray diffraction. The particle size distribution and the corresponding oxidation state was analyzed using transmission electron microscopy and X-ray absorption spectroscopy. The systematic study shows that oxidized Pt nanoparticles smaller than 2 nm sinter very fast, already at 600°C, but potential chlorine traces from the cat-alyst precursor seem to stabilize Pt nanoparticles against further sintering and consequently maintain the catalytic performance. Samples prepared by flame spray pyrolysis and laser abla-tion showed a superior hydrothermal resistance of the alumina support, although, due to small inter-particle distance in case of laser synthesized particles, the particle size distribution in-creases considerably at high temperatures. Significant deceleration of the noble metal sintering process was obtained for the catalysts containing homogeneously distributed but slightly larg-er Pt nanoparticles (supercritical fluid reactive deposition) or for particles deposited on a ther-mally stable alumina support (flame spray pyrolysis). The correlations obtained between Pt particle size distribution, oxidation state and catalytic performance indicate different trends for CO and NO oxidation reactions, in line with structure sensitivity.

Note: © American Chemical Society

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Contributing Institute(s):

1. DOOR-User (DOOR)

Research Program(s):

1. 6G3 - PETRA III (POF3-622) (POF3-622)

Experiment(s):

1. PETRA Beamline P64 (PETRA III)

Appears in the scientific report 2019

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

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