Journal Article

PUBDB-2023-00410

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Surface Noble Metal Concentration on Ceria as a Key Descriptor for Efficient Catalytic CO Oxidation

Maurer, F.Extern* ; Beck, A.Extern* ; Jelic, J. ; Wang, W. ; Mangold, S. ; Stehle, M. ; Wang, D. ; Dolcet, P. ; Gänzler, A. M.Extern* ; Kübel, C. ; Studt, F.Extern*XFEL.EU* ; Casapu, M.Extern* ; Grunwaldt, J.-D. (Corresponding author)Extern*

2022
ACS Washington, DC

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Please use a persistent id in citations: doi:10.1021/acscatal.1c04565  doi:10.3204/PUBDB-2023-00410

Abstract: During the CO oxidation over metallic Pt clusters and Pt nanoparticles in Pt/CeO$_2$ catalysts, we found that the Pt surface concentration is a key descriptor for the reaction rate. By increasing the surface noble metal concentration (SNMC) of a Pt/CeO$_2$ catalyst by a factor of ∼4, while keeping the weight hourly space velocity constant, the ignition temperature of CO oxidation was decreased by ∼200 °C in the as-prepared state. Moreover, the stability was enhanced at higher SNMC. Complementary characterization and theoretical calculations unraveled that the origin of this improved reaction rate at higher Pt surface concentrations can be traced back to the formation of larger oxidized Pt-clusters and the SNMC-dependent aggregation rate of highly dispersed Pt species. The Pt diffusion barriers for cluster formation were found to decrease with increasing SNMC, promoting more facile agglomeration of active, metallic Pt particles. In contrast, when Pt particle formation was forced with a reductive pretreatment, the influence of the SNMC was temporarily diminished, and all catalysts showed a similar CO oxidation activity. The work shows the general relevance of the proximity influence in the formation and stabilization of active centers in heterogeneous catalysis.

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Contributing Institute(s):

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

Research Program(s):

1. 6G3 - PETRA III (DESY) (POF4-6G3) (POF4-6G3)

Experiment(s):

1. PETRA Beamline P65 (PETRA III)

Appears in the scientific report 2022

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Essential Science Indicators ; IF >= 10 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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