Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Near-Surface Imaging of the Multicomponent Gas Phase above a Silver Catalyst during Partial Oxidation of Methanol

Zhou, Bo LU ; Huang, Erxiong ; Almeida, Raybel ; Gurses, Sadi ; Ungar, Alexander ; Zetterberg, Johan LU orcid ; Kulkarni, Ambarish ; Kronawitter, Coleman X. ; Osborn, David L. and Hansen, Nils , et al. (2021) In ACS Catalysis 11(1). p.155-168
Abstract

Fundamental chemistry in heterogeneous catalysis is increasingly explored using operando techniques in order to address the pressure gap between ultrahigh vacuum studies and practical operating pressures. Because most operando experiments focus on the surface and surface-bound species, there is a knowledge gap of the near-surface gas phase and the fundamental information the properties of this region convey about catalytic mechanisms. We demonstrate in situ visualization and measurement of gas-phase species and temperature distributions in operando catalysis experiments using complementary near-surface optical and mass spectrometry techniques. The partial oxidation of methanol over a silver catalyst demonstrates the value of these... (More)

Fundamental chemistry in heterogeneous catalysis is increasingly explored using operando techniques in order to address the pressure gap between ultrahigh vacuum studies and practical operating pressures. Because most operando experiments focus on the surface and surface-bound species, there is a knowledge gap of the near-surface gas phase and the fundamental information the properties of this region convey about catalytic mechanisms. We demonstrate in situ visualization and measurement of gas-phase species and temperature distributions in operando catalysis experiments using complementary near-surface optical and mass spectrometry techniques. The partial oxidation of methanol over a silver catalyst demonstrates the value of these diagnostic techniques at 600 Torr (800 mbar) pressure and temperatures from 150 to 410 °C. Planar laser-induced fluorescence provides two-dimensional images of the formaldehyde product distribution that show the development of the boundary layer above the catalyst under different flow conditions. Raman scattering imaging provides measurements of a wide range of major species, such as methanol, oxygen, nitrogen, formaldehyde, and water vapor. Near-surface molecular beam mass spectrometry enables simultaneous detection of all species using a gas sampling probe. Detection of gas-phase free radicals, such as CH3 and CH3O, and of minor products, such as acetaldehyde, dimethyl ether, and methyl formate, provides insights into catalytic mechanisms of the partial oxidation of methanol. The combination of these techniques provides a detailed picture of the coupling between the gas phase and surface in heterogeneous catalysis and enables parametric studies under different operating conditions, which will enhance our ability to constrain microkinetic models of heterogeneous catalysis.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; and (Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
catalytic partial oxidation of methanol, molecular beam mass spectrometry, planar laser-induced fluorescence, pressure gap, Raman scattering
in
ACS Catalysis
volume
11
issue
1
pages
14 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85098970016
ISSN
2155-5435
DOI
10.1021/acscatal.0c04396
language
English
LU publication?
yes
id
2e69629c-74ad-483e-a377-f49138e4ccf2
date added to LUP
2021-01-20 10:48:01
date last changed
2022-04-26 23:45:38
@article{2e69629c-74ad-483e-a377-f49138e4ccf2,
  abstract     = {{<p>Fundamental chemistry in heterogeneous catalysis is increasingly explored using operando techniques in order to address the pressure gap between ultrahigh vacuum studies and practical operating pressures. Because most operando experiments focus on the surface and surface-bound species, there is a knowledge gap of the near-surface gas phase and the fundamental information the properties of this region convey about catalytic mechanisms. We demonstrate in situ visualization and measurement of gas-phase species and temperature distributions in operando catalysis experiments using complementary near-surface optical and mass spectrometry techniques. The partial oxidation of methanol over a silver catalyst demonstrates the value of these diagnostic techniques at 600 Torr (800 mbar) pressure and temperatures from 150 to 410 °C. Planar laser-induced fluorescence provides two-dimensional images of the formaldehyde product distribution that show the development of the boundary layer above the catalyst under different flow conditions. Raman scattering imaging provides measurements of a wide range of major species, such as methanol, oxygen, nitrogen, formaldehyde, and water vapor. Near-surface molecular beam mass spectrometry enables simultaneous detection of all species using a gas sampling probe. Detection of gas-phase free radicals, such as CH3 and CH3O, and of minor products, such as acetaldehyde, dimethyl ether, and methyl formate, provides insights into catalytic mechanisms of the partial oxidation of methanol. The combination of these techniques provides a detailed picture of the coupling between the gas phase and surface in heterogeneous catalysis and enables parametric studies under different operating conditions, which will enhance our ability to constrain microkinetic models of heterogeneous catalysis. </p>}},
  author       = {{Zhou, Bo and Huang, Erxiong and Almeida, Raybel and Gurses, Sadi and Ungar, Alexander and Zetterberg, Johan and Kulkarni, Ambarish and Kronawitter, Coleman X. and Osborn, David L. and Hansen, Nils and Frank, Jonathan H.}},
  issn         = {{2155-5435}},
  keywords     = {{catalytic partial oxidation of methanol; molecular beam mass spectrometry; planar laser-induced fluorescence; pressure gap; Raman scattering}},
  language     = {{eng}},
  number       = {{1}},
  pages        = {{155--168}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{ACS Catalysis}},
  title        = {{Near-Surface Imaging of the Multicomponent Gas Phase above a Silver Catalyst during Partial Oxidation of Methanol}},
  url          = {{http://dx.doi.org/10.1021/acscatal.0c04396}},
  doi          = {{10.1021/acscatal.0c04396}},
  volume       = {{11}},
  year         = {{2021}},
}