Search results for " Catalyst"
showing 10 items of 292 documents
Wpływ wybranych parametrów na efektywność katalizowanej wanadocenem kopolimeryzacji etylenu z norbornenem i właściwości otrzymanych produktów
2019
W pracy zbadano wpływ parametrów reakcji na kopolimeryzację etylenu z norbornenem wobec katalizatora wanadocenowego (Cp2VCl2) w obecności trichloroctanu etylu (ETA). Przeprowadzono serię reakcji kopolimeryzacji, zmieniając w każdej z nich jeden z parametrów reakcji: temperaturę lub ciśnienie etylenu. Następnie zbadano temperaturę zeszklenia, stopień wbudowania norbornenu i mikrostrukturę otrzymanych kopolimerów, poddając je analizie DSC oraz spektroskopii 13C NMR. Wykazano wpływ badanych parametrów na aktywność katalizatora oraz ilość i sposób wbudowania jednostek norbornenu w łańcuch polimerowy, jak również wartość temperatury zeszklenia produktu. Stwierdzono, że właściwości otrzymanego ko…
Copolymerization of Ethylene with Selected Vinyl Monomers Catalyzed by Group 4 Metal and Vanadium Complexes with Multidentate Ligands: A Short Review
2021
This paper gives a short overview of homogeneous post-metallocene catalysts based on group 4 metal and vanadium complexes bearing multidentate ligands. It summarizes the catalytic behavior of those catalysts in copolymerization of ethylene with 1-olefins, with styrenic monomers and with α,ω-alkenols. The review is focused on finding correlations between the structure of a complex, its catalyst activity and comonomer incorporation ability, as well as the microstructure of the copolymer chains.
1-(1-Benzyl-2,5-dimethyl-4-phenyl-1H-pyrrol-3-yl)ethanone
2017
In the title compound, C21H21NO, the dihedral angles between the planes of the phenyl and pyrrole rings are 47.04 (5) and 79.27 (3)°. In the crystal, centrosymmetrically related molecules are linked into dimers by pairs of C—H...O hydrogen bonds, forming rings of graph-set motifR22(16).
Synthesis and characterization of ethylene-1-hexene copolymers prepared by using MgCl2(THF)2-supported Ziegler-Natta catalysts
2000
Ethylene was copolymerized with 1-hexene over vanadium (VOCl3 and VCl4) and titanium (TiCl4) catalysts supported on MgCl2(THF)2 and activated with Et2AlCl. So far these catalyst systems have not been known as initiators of ethylene-1-hexene copolymerization. The vanadium catalysts were more active than the titanium catalyst and, at identical comonomer concentrations in the feed, gave rise to a greater incorporation of 1-hexene into the copolymer. Even at relatively low fractions of 1-hexene, the MgCl2(THF)2-supported catalysts affected much the copolymer properties like density, melting point and crystallinity.
Feasibility of Waste Engine Oil Electrooxidation with Ni-Co and Cu-B Catalysts
2022
To implement a circular economy policy, methods of using waste products as a starting point for other technologies are constantly researched. One of the waste products that should be disposed of after use is waste engine oil (WEO). Despite the permanent introduction of the electrification of cars, the number of combustion vehicles (and, thus, the production of WEO) is constantly increasing. For these reasons, the reuse of WEOs is extremely important; e.g., to use these oils for energy purposes. One of the potential uses of this type of oil is as fuel for fuel cells (for direct electricity production). To lower the production costs of electrodes for fuel cells, catalysts that do not contain …
Preparation and Analysis of Ni–Co Catalyst Use for Electricity Production and COD Reduction in Microbial Fuel Cells
2019
Microbial fuel cells (MFCs) are devices than can contribute to the development of new technologies using renewable energy sources or waste products for energy production. Moreover, MFCs can realize wastewater pre-treatment, e.g., reduction of the chemical oxygen demand (COD). This research covered preparation and analysis of a catalyst and measurements of changes in the concentration of COD in the MFC with a Ni&ndash
Microwave-Assisted Esterification of Tall Oil Fatty Acids with Methanol Using Lignin-Based Solid Catalyst
2016
During alkaline pulping significant amounts of lignin, carbohydrates (mostly hemicelluloses), and extractives (tall oil soap and turpentine) are removed from wood feedstock. In this study, the catalytic esterification of fatty acids in tall oil with methanol to produce fatty acid methyl esters under microwave irradiation was performed at 100 °C for 10–60 min. A novel heterogeneous acid catalyst tested for this purpose was synthesized from the hardwood alkali lignin that was precipitated by acidification from the black liquor from soda-AQ pulping. The comparative reaction data were obtained by using other solid catalysts, Amberlyst 15, and p-toluenesulfonic acid. The results showed the highe…
Electrooxidation of methyl alcohol with Ni-Co catalyst
2018
Due to development of the renewable energy sources, the powering of fuel cells (FCs) with bio-fuels is very important. The one of this fuel is methyl alcohol. The use of fuel cells on a large scale is mainly limited by the high cost of catalysts – mainly platinum. Elimination of Pt as catalyst would allow for wider commercial application of FCs. The paper presents a study of methyl alcohol electrooxidation on electrode with NiCo alloy catalyst. Researches were done by the method of polarizing curves of electrooxidation of methanol in glass vessel. Conducted measurements show that there is a possibility of electrooxidation of methanol with Ni-Co catalyst. In any case, the process of electroo…
Methanol electrooxidation with Cu-B catalyst
2016
In the last few years alternative energy sources have been fast developing. One of these sources is fuel cell. Due to development of the renewable energy sources, the powering of fuel cells with bio-fuels is very important. The one of this fuel is methanol. The use of fuel cells on a large scale is mainly limited by the high cost of catalysts - mainly platinum. Elimination of Pt as catalyst would allow for wider commercial application of fuel cells. The paper presents a study of methanol electrooxidation on electrode with Cu-B alloy catalyst. Researches were done by the method of polarizing curves of electrooxidation of methanol in glass vessel. An aqueous solution of KOH was used as the el…