Loading…
Au/TiO2 supported on ferritic stainless steel monoliths as CO oxidation catalysts
[Display omitted] ► Au nanoparticles supported on TiO2 were coated over Aluchrom YHf monoliths. ► To favor the anchoring of the catalyst, metallic monoliths were previously calcined. ► The scale well adhered to the support was mainly composed of Al, Ti, Au, Ni and Mn. ► Ni and Mn enhanced the activi...
Saved in:
Published in: | Applied surface science 2013-04, Vol.270, p.169-177 |
---|---|
Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | [Display omitted]
► Au nanoparticles supported on TiO2 were coated over Aluchrom YHf monoliths. ► To favor the anchoring of the catalyst, metallic monoliths were previously calcined. ► The scale well adhered to the support was mainly composed of Al, Ti, Au, Ni and Mn. ► Ni and Mn enhanced the activity of Au/TiO2 for the oxidation of CO.
Metallic supported structured catalysts were obtained by washcoating AluchromYHf monoliths with an Au/TiO2 catalyst. The powder catalyst was synthesized by DAE (direct anionic exchange) method. Using this catalyst, a stable slurry was prepared and used to washcoat the monoliths. TEM and SEM studies revealed that gold nanoparticles in the Au/TiO2 powder catalyst had an average diameter of 3–4nm, but during the preparation of the structured catalyst, aggregate Au particles of the slurry reached diameters of 9nm. Before coating, Aluchrom YHf monoliths were thermally treated to generate a homogeneous and well-adhered oxide rough surface layer, mainly composed of α-Al2O3 whiskers, which favored the anchoring of the catalyst. The catalytic layer deposited was well attached and contained not only the Au/TiO2 catalyst but also metallic oxides formed from stainless steel components that diffused through the oxide scale. The structural characterization was performed by XRD, XRF, TEM, SEM, GD-OES and SBET.
The catalytic activity of the powder and structured catalysts was tested in the oxidation of the CO reaction. Catalysts demonstrated to be active at room temperature. After a first activation run, and in spite of their larger gold particle size, the catalytic activities of the structured catalysts overcame those of the powder catalyst. This improvement is probably due to the segregation of the transition metal oxides toward the surface oxide scale. |
---|---|
ISSN: | 0169-4332 1873-5584 |
DOI: | 10.1016/j.apsusc.2012.12.159 |