Single-Particle Catalysis: Revealing Intraparticle Pacemakers in Catalytic H2Oxidation on Rh
Journal article, 2021

Self-sustained oscillations in H2 oxidation on a Rh nanotip mimicking a single catalytic nanoparticle were studied by in situ field emission microscopy (FEM). The observed spatio-Temporal oscillations result from the coupling of subsurface oxide formation/depletion with reaction front propagation. An original sophisticated method for tracking kinetic transition points allowed the identification of local pacemakers, initiating kinetic transitions and the nucleation of reaction fronts, with much higher temporal resolution than conventional processing of FEM video files provides. The pacemakers turned out to be specific surface atomic configurations at the border between strongly corrugated Rh{973} regions and adjacent relatively flat terraces. These structural ensembles are crucial for reactivity: while the corrugated region allows sufficient oxygen incorporation under the Rh surface, the flat terrace provides sufficient hydrogen supply required for the kinetic transition, highlighting the importance of interfacet communication. The experimental observations are complemented by mean-field microkinetic modeling. The insights into the initiation and propagation of kinetic transitions on a single catalytic nanoparticle demonstrate how in situ monitoring of an ongoing reaction on individual nanofacets can single out active configurations, especially when combined with atomically resolving the nanoparticle surface by field ion microscopy (FIM).

interfacet communication

single-particle imaging

atomic arrangement

surface reaction

intraparticle pacemaker

nanoscale system

chemical oscillations


Johannes Zeininger

Vienna University of Technology

Y. Suchorski

Vienna University of Technology

M. Raab

Vienna University of Technology

S. Buhr

Vienna University of Technology

Henrik Grönbeck

Chalmers, Physics, Chemical Physics

G. Rupprechter

Vienna University of Technology

ACS Catalysis

21555435 (eISSN)

Vol. 11 15 10020-10027

Subject Categories

Inorganic Chemistry

Physical Chemistry

Other Chemistry Topics





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