Visualizing catalyst heterogeneity by a multifrequencial oscillating reaction
Artikel i vetenskaplig tidskrift, 2018

It is well documented that different surface structures of catalytically active metals may exhibit different catalytic properties. This is typically examined by comparing the catalytic activities and/or selectivities of various well-defined smooth and stepped/kinked single crystal surfaces. Here we report the direct observation of the heterogeneity of active polycrystalline surfaces under reaction conditions, which is manifested by multifrequential oscillations during hydrogen oxidation over rhodium, imaged in situ by photoemission electron microscopy. Each specific surface structure, i.e. the crystallographically different µm-sized domains of rhodium, exhibits an individual spiral pattern and oscillation frequency, despite the global diffusional coupling of the surface reaction. This reaction behavior is attributed to the ability of stepped surfaces of high-Miller-index domains to facilitate the formation of subsurface oxygen, serving as feedback mechanism of the observed oscillations. The current experimental findings, backed by microkinetic modeling, may open an alternative approach towards addressing the structure-sensitivity of heterogeneous surfaces.

Heterogeneous catalysis

Författare

J. Zeininger

Technische Universität Wien

Y. Suchorski

I. Bespalov

Technische Universität Wien

M. Datler

Technische Universität Wien

M. Stoger-Pollach

J. Bernardi

Henrik Grönbeck

Chalmers, Fysik, Kemisk fysik

G. Rupprechter

Nature Communications

2041-1723 (ISSN)

Vol. 9 600

Ämneskategorier

Oorganisk kemi

Materialkemi

Annan kemi

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Energi

Materialvetenskap

Fundament

Grundläggande vetenskaper

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1038/s41467-018-03007-3

Mer information

Skapat

2019-01-06