Cold Plasma Produced Catalytic Materials

The cold plasma techniques are widely applied to create new materials possessing unique properties, which cannot be prepared by any other methods. Among the many interesting substances produced with the participation of cold plasma, a special place is occupied by materials with catalytic properties. The chapter gives a brief review of various cold plasma methods used for the preparation of catalytic materials – from the plasma modification of conventional catalysts via plasma-enhanced classical synthesis of catalysts to the advanced thin catalytic films fabricated by plasma sputtering processes but primarily by plasma deposition from metalorganic precursors (PECVD). Recently, the catalytic films have attracted considerable attention due to the possibility of depositing them as very thin coatings on virtually all supports without any change in their geometry. Such coatings open the way for new reactor designs, so-called structured reactors, designated for various chemical processes. They can also be used as catalytic deposit on the surface of electrodes for fuel cells and photoelectrodes for water splitting processes. Recent developments in this field and further prospects for thin catalytic films are discussed, all the more so because it is one of the main areas of research in our department

Plasma Modified Polycarbonate Nonwovens as Filtering Material for Liquid Aerosols

The filter materials commonly used in filtration processes consist of nonwoven fabrics made by melt blowing. In order to improve filtration properties they are subjected to various modifications. This paper presents the treatment of polycarbonate nonwovens with lowpressure cold plasma generated by a 13.56 MHz RF discharge using process gases such as Ar and O2. The effectiveness of such treatment was assessed on the basis of results of the penetration of nonwovens by paraffin oil mist as well as the air flow resistance. The effects of plasma on polycarbonate nonwovens, especially on their surface morphology and chemical structure, were evaluated by electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The results indicate that Ar plasma is a good tool for improving the filtration properties of polycarbonate filtering materials. According to these results, the surface roughness plays an important role in the high-efficiency filtration of liquid aerosols with a small increase in air flow resistance

Towards Catalysts Prepared by Cold Plasma

Cold (non-equilibrium) plasma techniques have long been used as plasma deposition methods to create new materials, often with unique properties, which cannot be produced any other way, as well as plasma treatment methods for the sophisticated modification of conventional materials [...

Paladžio pagrindo plonų plėvių, nusodintų iš plazma aktyvintų metaloorganinių cheminių garų fazės, apibūdinimas

Darbe naudotas plazmos aktyvintas metaloorganinių garų cheminis nusodinimas (PEMOCVD) plonoms paladžio pagrindo plėvelėms sudaryti, kaip pirmtaką naudojant paladžio (II) acetilacetonatą (Pd(acac)2), sumaišytą su argonu (nešančiosios dujos). Plėvių cheminei sandarai ir morfologijai tirti naudota Ramano spektroskopija ir elektronų difrakcija. Energijos dispersinė rentgeno spindulių mikroanalizė (EDX) buvo taikoma plėvelių sudėčiai nustatyti. Plėvelės storis buvo įvertintas elipsometriniais matavimais. Rezultatai rodo, kad priklausomai nuo nusodinimo sąlygų, gaunamos skirtingos sudėties plėvelės. Taip pat nustatyta, kad, esant 623 K temperatūrai, plėvelės suyra ir dėl to formuojasi 5 nm – 10 nm dydžio katalitiškai aktyvios paladžio nanodalelės.DOI: http://dx.doi.org/10.5755/j01.ms.18.2.1913</p

Plasma Deposited Thin Iron Oxide Films as Electrocatalyst for Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells

The possibility of using plasma deposited thin films of iron oxides as electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFC) was examined. Results of energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) analysis indicated that the plasma deposit consisted mainly of FeOX structures with the X parameter close to 1.5. For as deposited material iron atoms are almost exclusively in the Fe3+ oxidation state without annealing in oxygen containing atmosphere. However, the annealing procedure can be used to remove the remains of carbon deposit from surface. The single cell test (SCT) was performed to determine the suitability of the produced material for ORR. Preliminary results showed that power density of 0.23 mW/cm2 could be reached in the tested cell.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14406</p