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In situ NAP-XPS spectroscopy during methane dry reforming on ZrO 2 /Pt(1 1 1) inverse model catalyst.

In situ NAP-XPS spectroscopy during methane dry reforming on ZrO 2 /Pt(1 1 1) inverse model catalyst.

Authors :
Rameshan C
Li H
Anic K
Roiaz M
Pramhaas V
Rameshan R
Blume R
Hävecker M
Knudsen J
Knop-Gericke A
Rupprechter G
Source :
Journal of physics. Condensed matter : an Institute of Physics journal [J Phys Condens Matter] 2018 Jul 04; Vol. 30 (26), pp. 264007. Date of Electronic Publication: 2018 May 22.
Publication Year :
2018

Abstract

Due to the need of sustainable energy sources, methane dry reforming is a useful reaction for conversion of the greenhouse gases CH <subscript>4</subscript> and CO <subscript>2</subscript> to synthesis gas (CO  +  H <subscript>2</subscript> ). 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 <subscript>2</subscript> /Pt inverse model catalyst, i.e. ZrO <subscript>2</subscript> 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 <subscript>4</subscript> ) the ZrO <subscript>2</subscript> particles transformed to an ultrathin ZrO <subscript>2</subscript> 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 <subscript>4</subscript> and CO <subscript>2</subscript> were stabilizing the ZrO <subscript>2</subscript> 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 <subscript>4</subscript> dissociation were easily removed by CO <subscript>2</subscript> 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 <subscript>2</subscript> /Pt interface.

Details

Language :
English
ISSN :
1361-648X
Volume :
30
Issue :
26
Database :
MEDLINE
Journal :
Journal of physics. Condensed matter : an Institute of Physics journal
Publication Type :
Academic Journal
Accession number :
29786619
Full Text :
https://doi.org/10.1088/1361-648X/aac6ff