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In situ NAP-XPS spectroscopy during methane dry reforming on ZrO2/Pt(1 1 1) inverse model catalyst

Rameshan, C.; Li, H.; Anic, K.; Roiaz, M.; Pramhaas, V.; Rameshan, R.; Blume, R.; Hävecker, M.; Knudsen, J. LU and Knop-Gericke, A., et al. (2018) In Journal of Physics Condensed Matter 30(26).
Abstract

Due to the need of sustainable energy sources, methane dry reforming is a useful reaction for conversion of the greenhouse gases CH4 and CO2 to synthesis gas (CO + H2). Syngas is the basis for a wide range of commodity chemicals and can be utilized for fuel production via Fischer-Tropsch synthesis. The current study focuses on spectroscopic investigations of the surface and reaction properties of a ZrO2/Pt inverse model catalyst, i.e. ZrO2 particles (islands) grown on a Pt(1 1 1) single crystal, with emphasis on in situ near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) during MDR reaction. In comparison to technological systems, model catalysts facilitate... (More)

Due to the need of sustainable energy sources, methane dry reforming is a useful reaction for conversion of the greenhouse gases CH4 and CO2 to synthesis gas (CO + H2). Syngas is the basis for a wide range of commodity chemicals and can be utilized for fuel production via Fischer-Tropsch synthesis. The current study focuses on spectroscopic investigations of the surface and reaction properties of a ZrO2/Pt inverse model catalyst, i.e. ZrO2 particles (islands) grown on a Pt(1 1 1) single crystal, with emphasis on in situ near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) during MDR reaction. In comparison to technological systems, model catalysts facilitate characterization of the surface (oxidation) state, surface adsorbates, and the role of the metal-support interface. Using XPS and infrared reflection absorption spectroscopy we demonstrated that under reducing conditions (UHV or CH4) the ZrO2 particles transformed to an ultrathin ZrO2 film that started to cover (wet) the Pt surface in an SMSI-like fashion, paralleled by a decrease in surface/interface oxygen. In contrast, (more oxidizing) dry reforming conditions with a 1:1 ratio of CH4 and CO2 were stabilizing the ZrO2 particles on the model catalyst surface (or were even reversing the strong metal support interaction (SMSI) effect), as revealed by in situ XPS. Carbon deposits resulting from CH4 dissociation were easily removed by CO2 or by switching to dry reforming conditions (673-873 K). Thus, at these temperatures the active Pt surface remained free of carbon deposits, also preserving the ZrO2/Pt interface.

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published
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keywords
catalysis, in situ XPS, inverse model catalyst, IRAS, methane dry reforming, strong metal-support interaction (SMSI), surface structure
in
Journal of Physics Condensed Matter
volume
30
issue
26
publisher
IOP Publishing
external identifiers
  • scopus:85049055808
ISSN
0953-8984
DOI
10.1088/1361-648X/aac6ff
language
English
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yes
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34ee88e4-5d8b-4168-8f57-cfe06ada7292
date added to LUP
2018-07-06 12:51:11
date last changed
2018-07-07 03:00:04
@article{34ee88e4-5d8b-4168-8f57-cfe06ada7292,
  abstract     = {<p>Due to the need of sustainable energy sources, methane dry reforming is a useful reaction for conversion of the greenhouse gases CH<sub>4</sub> and CO<sub>2</sub> to synthesis gas (CO + H<sub>2</sub>). Syngas is the basis for a wide range of commodity chemicals and can be utilized for fuel production via Fischer-Tropsch synthesis. The current study focuses on spectroscopic investigations of the surface and reaction properties of a ZrO<sub>2</sub>/Pt inverse model catalyst, i.e. ZrO<sub>2</sub> particles (islands) grown on a Pt(1 1 1) single crystal, with emphasis on in situ near ambient pressure x-ray photoelectron spectroscopy (NAP-XPS) during MDR reaction. In comparison to technological systems, model catalysts facilitate characterization of the surface (oxidation) state, surface adsorbates, and the role of the metal-support interface. Using XPS and infrared reflection absorption spectroscopy we demonstrated that under reducing conditions (UHV or CH<sub>4</sub>) the ZrO<sub>2</sub> particles transformed to an ultrathin ZrO<sub>2</sub> film that started to cover (wet) the Pt surface in an SMSI-like fashion, paralleled by a decrease in surface/interface oxygen. In contrast, (more oxidizing) dry reforming conditions with a 1:1 ratio of CH<sub>4</sub> and CO<sub>2</sub> were stabilizing the ZrO<sub>2</sub> particles on the model catalyst surface (or were even reversing the strong metal support interaction (SMSI) effect), as revealed by in situ XPS. Carbon deposits resulting from CH<sub>4</sub> dissociation were easily removed by CO<sub>2</sub> or by switching to dry reforming conditions (673-873 K). Thus, at these temperatures the active Pt surface remained free of carbon deposits, also preserving the ZrO<sub>2</sub>/Pt interface.</p>},
  articleno    = {264007},
  author       = {Rameshan, C. and Li, H. and Anic, K. and Roiaz, M. and Pramhaas, V. and Rameshan, R. and Blume, R. and Hävecker, M. and Knudsen, J. and Knop-Gericke, A. and Rupprechter, G.},
  issn         = {0953-8984},
  keyword      = {catalysis,in situ XPS,inverse model catalyst,IRAS,methane dry reforming,strong metal-support interaction (SMSI),surface structure},
  language     = {eng},
  month        = {06},
  number       = {26},
  publisher    = {IOP Publishing},
  series       = {Journal of Physics Condensed Matter},
  title        = {In situ NAP-XPS spectroscopy during methane dry reforming on ZrO<sub>2</sub>/Pt(1 1 1) inverse model catalyst},
  url          = {http://dx.doi.org/10.1088/1361-648X/aac6ff},
  volume       = {30},
  year         = {2018},
}