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Introduction Raney metal type catalysts are prepared by leaching the reactive material out from alloys of catalytically active transition metals such as nickel, cobalt, iron, copper and a reactive material such as aluminum with
electrolytes in lithium–ion batteries [ 5 – 8 ]. For such coupling reactions, many types of catalysts such as alkali metal salts [ 9 – 11 ], metal oxides [ 12 – 15 ], transition metal complexes [ 16 – 19 ], Schiff bases [ 20 , 21 ], ion-exchange resins [ 22
in various oxidation reactions as cheap and clear oxidant from the viewpoint of green chemistry [ 4 – 7 ]. Polyoxometalates, as the effective catalysts for oxidation reactions with H 2 O 2 have drawn wide attention in the past years. Most procedures
Abstract
The purpose of this work was to employ the differential thermal analysis (DTA) technique to compare variations in the collapse energy of the zeolite Y crystalline structure in a fresh catalyst and in the same catalyst impregnated with nickel and vanadium. A small exothermic signal in the DTA curve at 950–1150 °C indicated the collapse of the crystalline structure. The areas of the exothermic signals in the DTA curves of the two samples indicated a reduction in the curve of the metal impregnated catalyst. These results were compared with X-ray data, leading to the conclusion that metal impregnation affects the zeolite Y crystalline structure and that the DTA technique is a potentially useful tool for measuring the integrity of zeolite Y in catalysts.
., or mineral acids HF or polyphosphoric acid as homogeneous catalysts are employed for aromatic acylation [ 3 ]. Unfortunately, use of such conventional catalysts is associated with a number of problems. Such processes consume near stoichiometric
(PhCN) 2 ], rhodium [ 7 ] [RhH(PPh 3 ) 4 ], ruthenium [ 8 ] [Ru 3 (CO) 12 ], and iridium [ 9 ] {[IrCl(COD)] 2 } catalysts. Although these catalysts are active for the reaction, they are significantly expensive and non-recoverable [ 10 ]. Compared with
Introduction The hydrogenation of mononitroaromatic compounds to aromatic amines is ordinarily carried out in vapor-phase reactions using either a fixed bed or fluidized catalyst. However, the low vapor pressures and thermal
Introduction Titanium dioxide is applied to the preparation of the catalysts used in the oxidation and ammoxidation of alkylbenzenes and alkylpyridines [ 1 ]. A crystal modification of titanium dioxide influences on the
calculated from the slope of the linear plots of the volume of oxygen uptake vs. time. All kinetic measurements were carried out by using freshly prepared samples. The catalysts were characterized by comparison of their physical properties with those
32 Escardino A., Amoros J. L., Moreno A., Sanchez E. Utilizing the used catalyst from refinery fcc units as a substitute for kaolin in formulating ceramic frits, Waste Management and
