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EN
The comparative study of iron-aluminum binary oxides Fe2-xAlxO3 (where x = 2/3, 1, 4/3) reduction behavior was investigated and the obtained bi-oxides were characterzed by TPR, TG-DTA, BET and XRD methods. In hydrogen atmosphere three step reduction path way for iron-aluminum binary oxide was found. Such reduction behavior appeared reasonably analogical to that characteristic of hematite type iron(III) oxide reduction 3Fe2O3 rightwards arrow 2Fe3O4 rightwards arrow 6FeO rightwards arrow 6Fe. The reduction for unimolar bi-oxide Fe2-xAlxO3 (x = 1) can be expressed in following way: 4FeAlO3 rightwards arrow 2Fe2AlO4 rightwards arrow 2FeAl2O4 + 2Fe rightwards arrow 4Fe but the last step of reduction was not accomplished below 1000°C. In air FeAlO3 bi-oxide decomposes above 1300°C, whereas exothermal dissociation 2FeAlO3 rightwards arrow alfa-Al2O3 and alfa-Fe2O3 above 770°C was con firmed in argon atmosphere.
EN
Characterization of bimetallic Cu-Ag and Cu-Au catalytic systems supported on CrAl3O6 was carried out by TOF-SIMS, XRD and SEM-EDS techniques. The evidence of alloying of copper and second metal was observed during catalyst reduction as well as methanol syntheis reaction. The promoting effect of noble metal catalysts on copper catalyst was noticed. Modification by gold or silver improves activity up to ten times.
EN
The influence of copper and noble metal (Ag, Au) addition on the physicochemical properties of support FeAlO3 and supported metal catalysts was studied. The reaction of methanol formation in the temperature range 200-380 graduate C under atmospheric pressure over a series of Cu and M-Cu catalysts (where M = Ag, Au) has been investigated. The presence of spinel like type structures FeAlO3, Fe2AlO4 and FeAl2O4 was confirmed by XRD technique. The physicochemical properties of supports and supported copper and bimetallic Ag, Au-Cu/FeAlO3 catalysts were examined by BET, TPR, and XRD methods.
EN
The gold influence on catalytic activity, stability and carbon deposition of supported nickel based catalysts was studied. The monometallic 5%Ni/Al2O3 and bimetallic 5%Ni-x%Au/Al2O3 (x = 2, 1, 0.5, 0.25, 0.1) systems were prepared by wet impregnation. The catalytic tests in partial oxidation of methane at 25-900 graduate C and long term stability tests at 900 graduate C during 24 h were carried out. The CH4 dissociative decomposition and CO disproportionation processes were run at the same temperature range. Carbon deposition was studied by TG analysis and catalysts investigations by TPR and XRD measurements. The results indicated that gold addition improved both catalytic activity and resistance towards carbon deposition.
EN
The aim of this work was the determination of the effect of support and gold promotion on physicochemical properties, and catalytic activity in partial oxidation of methane and methanol synthesis. The kind and amount of coke deposition formed during partial methane oxidation (POM) and methanol synthesis (MS) were determined. The influence of gold addition on physicochemical properties of mono- and bimetallic (Cu, Fe, Ni) spinel (MgAl2O4, FeAlO3, ZnAl2O4, CrAl3O6) supported catalysts was determined. It was found that modification by gold-copper or nickel supported catalysts have no strong influence on their reducibility. Catalytic activity almost does not change before and after gold introduction for POM reaction and increases significantly for MS reaction. In both cases gold promotion decreases coke formation and makes easier its oxidation.
EN
Determination of trace elements in combusted materials has always been an interesting field of environmental studies. Particulate matter, in particular, is a serious problem which, can lead to air pollution especially by heavy metals emissions in urban and industrial areas. There is a considerable concern about the elevated level of mercury released during combustion and the proportion of anthropogenic mercury in the environment. Nowadays, small-scale installations have been identified as a significant source-pathway for mercury pollution, particularly those that use coal. A total amount of mercury was determined using Mercury Analyzer. The investigated material consists of bottom ash, fly ash, slag, soot or dust. The obtained results varied according to the type of the material and plant. The developed methodology was checked by carrying out the analysis of certificate material of Soil NCS ZC 73001 and the reference material of Soil-7.
EN
The aim of this work was the ToF-SIMS investigations of different particles arising as a result of a coal combustion process in selected power plants from Central Poland. The chemical composition and distribution of particular compounds on the studied surfaces were determined. Moreover, the ratio of the quantity of aromatic and aliphatic hydrocarbons adsorbed on the surface of the particles was estimated. A qualitative analysis of the studied samples demonstrated the presence of a big number of various compounds, including heavy metals such as Pb, Cd and As on the investigated surfaces. In the prevailing number sample components were distributed non-homogenously on the surface and the larger areas richer in a certain type of ions were observed.
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