W-containing oxide layers obtained on aluminum and titanium by PEO as catalysts in thiophene oxidation

• Published in: Applied surface science Vol. 422; pp. 1007 - 1014
• Main Authors: Rudnev, V.S., Lukiyanchuk, I.V., Vasilyeva, M.S., Morozova, V.P., Zelikman, V.M., Tarkhanova, I.G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-11-2017
• Subjects: Metal-supported catalysts; Plasma electrolytic oxidation; Thiophene oxidation; W-containing coatings; W-containing coatings; Metal-supported catalysts; Thiophene oxidation; Plasma electrolytic oxidation
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2017.06.071

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•W-containing PEO coatings of two types were tested in thiophene oxidation by H2O2.•Coatings I had low W concentration, coatings II contained WO3 and/or Al2(WO4)3.•Coatings I: more stability+lowerC4H4S conversion under higher initial oxidation rates.•Coatings II: low stability+higherC4H4S conversion under low initial rates.•Al-Mn-supported coatings with 0.7 at% W showed higher TOF and were most stable.
W-containing oxide layers fabricated on titanium and aluminum alloys by Plasma electrolytic oxidation (PEO) have been tested in the reaction of the peroxide oxidation of thiophene. Samples with two types of coatings have been investigated. Coatings I contained tungsten oxide in the matrix and on the surface of amorphous silica-titania or silica-alumina layers, while coatings II comprised crystalline WO3 and/or Al2(WO4)3. Aluminum-supported catalyst containing a smallest amount of transition metals in the form of tungsten oxides and manganese oxides in low oxidation levels showed high activity and stability.