Application of oxide-metallic catalysts on valve metals for ecological catalysis

Advances in Materials Science and Engineering

et al. 2019

is paper presents the results of studies on the electrochemical treatment characteristics of aluminum and alloys in alkaline electrolytes. It is shown that the heterogeneity of the alloys composition complicates the formation of the surface oxide layer. To homogenize the treated surface and obtain oxide coatings doped with manganese and cobalt, electrolytes based on KOH and K 4 P 2 O 7 with the addition of KMnO 4 and CoSO 4 were used. Plasma electrolytic oxidizing (PEO) in these electrolytes in the range of current densities 5-20 A/dm 2 allows to obtain mixed oxide coatings which contained both aluminum oxide matrix and doping metal oxides Al 2 O 3 ·MnO x and Al 2 O 3 ·CoO y . It is shown that an increase in the PEO current density and the concentration of manganate-and cobalt(II) ions in the solution leads to an increase the content of dopant metals in the coatings outer layer. e incorporation of manganese and cobalt oxides in the composition of the surface layers was confirmed by the results of X-ray structural analysis. e rational modes of aluminum alloys PEO treatment were substantiated to obtain coatings with manganese and cobalt contents up to 25-40 at.%. Formed oxide systems have a developed surface and high adhesion to the base metal and show an increased corrosion resistance and catalytic activity. is allows us to view them as promising materials for air-and watercleaning technologies and internal combustion engine waste gas purification systems.

Section: Plasma Electrolytic Oxide Coatings Obtained Using K 4 P 2 O mentioning

confidence: 99%

Features of Plasma Electrolytic Formation of Manganese- and Cobalt-Containing Composites on Aluminum Alloys

Advances in Materials Science and Engineering

et al. 2019

“…So, it can be regarded as an additional indicator of the surface development during oxidation [21,25]. Estimating the topography of the titanium alloy VT1-0 surface oxidized in potassium diphosphate, we can conclude the coatings to be unevenly rough (Figure 8).…”

Section: Resultsmentioning

confidence: 99%

Effect of Doping Metals on the Structure of PEO Coatings on Titanium

International Journal of Chemical Engineering

2018

e structure and properties of the oxide films formed on titanium alloys by means of plasma-electrolytic oxidizing in alkali electrolytes based on pyrophosphates, borates, or acetates of alkali metals with the addition of dopants' oxides or oxoanions of varying composition have been studied. Anodic polarization in the spark discharge (microarc) mode at application of interelectrode potential 90 to 160 V has been used to obtain mixed-oxide systems TiO x ·WO y , TiO x ·MoO y , TiO x ·ZrO 2 , and TiO x ·V 2 O 5 . e possibility to obtain the oxide layers containing the alloying elements by the modification of the composition of electrolytes has been stated. e chemical and phase composition as well as the topography, the microstructure, and the grain size of the formed layers depend on the applied current, interelectrode voltage, and the layer chemical composition. e effect of formed films composition on the resistance of titanium to corrosion has been discussed. Catalytic activity of mixed-oxide systems was determined in the model reaction of methyl orange dye MO photodestruction.

“…The obtained cobalt-containing oxide coatings could be applied in toxins neutralization technologies, specifically, in air and water purification systems, to reduce the toxicity of gas emissions from internal combustion engines [26,34].…”

Section: Discussion Of the Effect Of Electrolyte Components Ratio On mentioning

confidence: 99%

Study into formation of cobalt-containing peo-coatings on АК12М2МgN from a pyrophosphate electrolyte

et al. 2017

EEJET

Self Cite

Досліджено формування кобальтовмісних оксидних покривів методом плазмово-електролітичного оксидування силуміну АК12М2МгН у пірофосфатних електролітах. Показано, що варіювання концентрації кобальту сульфату в розчині впливає на робочі параметри ПЕО. Встановлено, що склад та морфологія сформованих оксидних шарів залежать від співвідношення компонентів електроліту. Це дозволяє керувати процесом інкорпорації допанта в матрицю оксиду алюмінія. Обгрунтовано склад пірофосфатного електроліту для одержання оксидних покривів, збагачених каталітичним компонентом Ключові слова: оксидний покрив, силумін, АК12М2МгН, плазмово-електролітичне оксидування, пірофосфатний електроліт, морфологія поверхні Исследовано формирование кобальтосодержащих оксидных покрытий методом плазменно-электролитического оксидирования силумина АК12М2МгН в пирофосфатных электролитах. Показано, что варьирование концентрации кобальта сульфата в растворе влияет на рабочие параметры ПЭО. Установлено, что состав и морфология сформированных оксидных слоев зависят от соотношения компонентов электролита. Это позволяет управлять процессом инкорпорации допанта в матрицу оксида алюминия. Обоснован состав пирофосфатного электролита для получения оксидных покрытий, обогащенных каталитическим компонентом Ключевые слова: оксидное покрытие, силумин, АК12М2МгН, плазменно-электролитическое оксидирование, пирофосфатный электролит, морфология поверхности