Chemically resolved dynamical imaging of catalytic reactions on composite surfaces

F. Esch; S. Günther; E. Schütz; A. Schaak; I. G. Kevrekidis; M. Marsi; M. Kiskinova; R. Imbihl

Chemically resolved dynamical imaging of catalytic reactions on composite surfaces

F. Esch, S. Günther, E. Schütz, A. Schaak, I. G. Kevrekidis, M. Marsi, M. Kiskinova, R. Imbihl

Chemical & Biological Engineering

Research output: Contribution to journal › Article › peer-review

19 Scopus citations

Abstract

The catalytic reduction of NO by hydrogen is investigated at T = 650 K and p ≈ 10^-6 CT mbar on a microstructured Rh/Pt(100) surface consisting of Pt(100) domains surrounded by a 600 Å thick Rh film. Synchrotron radiation scanning photoemission microcopy (SPEM), using photons focused into a spot of less then 0.2 μm diameter, is employed as a spatially and chemically resolving in situ technique. The chemical wave, which arise in the bistable system NO + H₂/Rh are imaged with SPEM monitoring the N 1s and O 1s photoelectrons. The reaction fronts initiate transitions from an inactive oxygen-covered surface (Θ_O ≈ 0.25 ML) to a reactive nitroeen-covered surface (Θ_N ≈ 0.06 ML) At the Pt/Rh interface, synergetic effects can be observed: the chemical waves on the Rh film nucleate preferentially at the Pt/Rh interface. This nucleation is poisoned by carbon contamination on the Pt area but is prevented in the vicinity of the Pt/Rh interface by the adjacent clean Rh film. No segregation of Pt to the surface was observed for the 600 Å thick Rh film.

Original language	English (US)
Pages (from-to)	85-90
Number of pages	6
Journal	Catalysis Letters
Volume	52
Issue number	1
State	Published - Jan 1 1998

All Science Journal Classification (ASJC) codes

Catalysis
General Chemistry

Keywords

Chemical waves
Dynamical imaging
Microstructured composite surfaces
NO reduction
PEEM
Photoemission electron microscopy
Pt
Rh
SPEM
Scanning photoemission microscopy

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@article{39faec3e26ad491ea0e0b4289dd18919,

title = "Chemically resolved dynamical imaging of catalytic reactions on composite surfaces",

abstract = "The catalytic reduction of NO by hydrogen is investigated at T = 650 K and p ≈ 10-6 CT mbar on a microstructured Rh/Pt(100) surface consisting of Pt(100) domains surrounded by a 600 {\AA} thick Rh film. Synchrotron radiation scanning photoemission microcopy (SPEM), using photons focused into a spot of less then 0.2 μm diameter, is employed as a spatially and chemically resolving in situ technique. The chemical wave, which arise in the bistable system NO + H2/Rh are imaged with SPEM monitoring the N 1s and O 1s photoelectrons. The reaction fronts initiate transitions from an inactive oxygen-covered surface (ΘO ≈ 0.25 ML) to a reactive nitroeen-covered surface (ΘN ≈ 0.06 ML) At the Pt/Rh interface, synergetic effects can be observed: the chemical waves on the Rh film nucleate preferentially at the Pt/Rh interface. This nucleation is poisoned by carbon contamination on the Pt area but is prevented in the vicinity of the Pt/Rh interface by the adjacent clean Rh film. No segregation of Pt to the surface was observed for the 600 {\AA} thick Rh film.",

keywords = "Chemical waves, Dynamical imaging, Microstructured composite surfaces, NO reduction, PEEM, Photoemission electron microscopy, Pt, Rh, SPEM, Scanning photoemission microscopy",

author = "F. Esch and S. G{\"u}nther and E. Sch{\"u}tz and A. Schaak and Kevrekidis, {I. G.} and M. Marsi and M. Kiskinova and R. Imbihl",

year = "1998",

month = jan,

day = "1",

language = "English (US)",

volume = "52",

pages = "85--90",

journal = "Catalysis Letters",

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publisher = "Springer Netherlands",

number = "1",

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TY - JOUR

T1 - Chemically resolved dynamical imaging of catalytic reactions on composite surfaces

AU - Esch, F.

AU - Günther, S.

AU - Schütz, E.

AU - Schaak, A.

AU - Kevrekidis, I. G.

AU - Marsi, M.

AU - Kiskinova, M.

AU - Imbihl, R.

PY - 1998/1/1

Y1 - 1998/1/1

N2 - The catalytic reduction of NO by hydrogen is investigated at T = 650 K and p ≈ 10-6 CT mbar on a microstructured Rh/Pt(100) surface consisting of Pt(100) domains surrounded by a 600 Å thick Rh film. Synchrotron radiation scanning photoemission microcopy (SPEM), using photons focused into a spot of less then 0.2 μm diameter, is employed as a spatially and chemically resolving in situ technique. The chemical wave, which arise in the bistable system NO + H2/Rh are imaged with SPEM monitoring the N 1s and O 1s photoelectrons. The reaction fronts initiate transitions from an inactive oxygen-covered surface (ΘO ≈ 0.25 ML) to a reactive nitroeen-covered surface (ΘN ≈ 0.06 ML) At the Pt/Rh interface, synergetic effects can be observed: the chemical waves on the Rh film nucleate preferentially at the Pt/Rh interface. This nucleation is poisoned by carbon contamination on the Pt area but is prevented in the vicinity of the Pt/Rh interface by the adjacent clean Rh film. No segregation of Pt to the surface was observed for the 600 Å thick Rh film.

AB - The catalytic reduction of NO by hydrogen is investigated at T = 650 K and p ≈ 10-6 CT mbar on a microstructured Rh/Pt(100) surface consisting of Pt(100) domains surrounded by a 600 Å thick Rh film. Synchrotron radiation scanning photoemission microcopy (SPEM), using photons focused into a spot of less then 0.2 μm diameter, is employed as a spatially and chemically resolving in situ technique. The chemical wave, which arise in the bistable system NO + H2/Rh are imaged with SPEM monitoring the N 1s and O 1s photoelectrons. The reaction fronts initiate transitions from an inactive oxygen-covered surface (ΘO ≈ 0.25 ML) to a reactive nitroeen-covered surface (ΘN ≈ 0.06 ML) At the Pt/Rh interface, synergetic effects can be observed: the chemical waves on the Rh film nucleate preferentially at the Pt/Rh interface. This nucleation is poisoned by carbon contamination on the Pt area but is prevented in the vicinity of the Pt/Rh interface by the adjacent clean Rh film. No segregation of Pt to the surface was observed for the 600 Å thick Rh film.

KW - Chemical waves

KW - Dynamical imaging

KW - Microstructured composite surfaces

KW - NO reduction

KW - PEEM

KW - Photoemission electron microscopy

KW - Pt

KW - Rh

KW - SPEM

KW - Scanning photoemission microscopy

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M3 - Article

SN - 1011-372X

VL - 52

SP - 85

EP - 90

JO - Catalysis Letters

JF - Catalysis Letters

IS - 1

ER -

Chemically resolved dynamical imaging of catalytic reactions on composite surfaces

Abstract

All Science Journal Classification (ASJC) codes

Keywords

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