Influence of the nature and amount of the second component of binary-palladium alloys on their catalytic activity with respect to the dehydrogenation of cyclohexane

1970 ◽  
Vol 19 (11) ◽  
pp. 2368-2371 ◽  
Author(s):  
V. M. Gryaznov ◽  
V. P. Polyakova ◽  
E. M. Savitskii ◽  
L. Frades ◽  
E. V. Khrapova ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Alloys ◽  
Dehydrogenation Of Cyclohexane

Catalytic Activity of Ni/(P)Ti-HMS Catalysts with Varying Phosphorous Concentration in The reaction Of dehydrogenation of Cyclohexane

1998 ◽  
Vol 549 ◽  
Author(s):  
T. Halachev ◽  
T. Viveros ◽  
G. Perez ◽  
L. Dimitrov
Keyword(s):  
Catalytic Activity ◽  
Surface Properties ◽  
Mesoporous Materials ◽  
Acid Base ◽  
Base Surface ◽  
Cyclohexane Dehydrogenation ◽  
Dehydrogenation Of Cyclohexane ◽  
Phosphorous Concentration

AbstractNi/(P)Ti-HMS catalysts were prepared and characterized by several physicochernical techniques. The addition of phosphorous to the original mesoporous materials modified the acid-base surface properties. The activity in cyclohexane dehydrogenation is higher than on conventional catalysts.

Sonochemical Synthesis and Catalytic Properties of Nanostructured Molybdenum Carbide

1994 ◽  
Vol 351 ◽  
Author(s):  
Kenneth S. Suslick ◽  
Taeghwan Hyeon ◽  
Mingming Fang ◽  
Andrzej A. Cichowlas
Keyword(s):  
Catalytic Activity ◽  
Molybdenum Carbide ◽  
Gas Adsorption ◽  
High Surface ◽  
High Surface Area ◽  
Face Centered Cubic ◽  
Excess Carbon ◽  
Dehydrogenation Of Cyclohexane ◽  
Good Catalytic Activity ◽  
Face Centered

ABSTRACTMolybdenum hexacarbonyl in hexadecane was irradiated with high intensity ultrasound under argon at 90°C to yield face centered cubic molybdenum carbide, Mo2C. After thermal treatment, oxygen and excess carbon were removed to give stoichiometric Mo2C. SEM micrographs showed that the surface was extremely porous. TEM micrographs showed that the solid was an aggregate of particles with diameters of ≈ 2 nm. This material has a very high surface area, 188 m2/g as determined by BET gas adsorption. Catalytic studies have been conducted on the dehydrogenation of cyclohexane and the hydrogenolysis of ethane. The sonochemically prepared Mo2C shows good catalytic activity for the dehydrogenation of cyclohexane with 100% selectivity for formation of benzene without hydrogenolysis to methane. The material revealed poor catalytic activity for the hydrogenolysis of ethane.

Nanostructured Fe-Co Catalysts Generated by Ultrasound

1994 ◽  
Vol 351 ◽  
Author(s):  
Kenneth S. Suslick ◽  
Mingming Fang ◽  
Taeghwan Hyeon ◽  
Andrzej A. Cichowlas
Keyword(s):  
Catalytic Activity ◽  
High Surface ◽  
Pure Metal ◽  
High Catalytic Activity ◽  
Small Surface ◽  
Co Catalysts ◽  
Surface Areas ◽  
Alloy Particles ◽  
Dehydrogenation Of Cyclohexane ◽  
Co Alloys

ABSTRACTBimetallic catalysts have been studied intensively because of their unique activity and selectivity. Unsupported alloy catalysts, however, are usually of limited value due to their very small surface areas. We have now developed a sonochemical synthesis of bimetallic alloys that provides both high surface areas and high catalytic activity. We have produced Fe-Co alloys by ultrasonic irradiation of mixed solutions of Fe(CO)5 and Co(CO)3(NO) in hydrocarbon solvents. The alloy composition can be controlled simply by changing the ratio of precursor concentrations. After treatment at 673K under H2 flow for 2 hours, we obtain nearly pure alloys. BET results show that the surface areas of these alloys are large (10-30 m2/g). TEM and SEM show that the alloy particles are porous agglomerates of particles with diameters of 10-20 nm. Sonochemically prepared Fe, Co, and Fe-Co powders have very high catalytic activity for dehydrogenation and hydrogenolysis of cyclohexane. Furthermore, sonochemically prepared Fe-Co alloys show high catalytic selectivity for dehydrogenation of cyclohexane to benzene; the 1:1 ratio alloy has much higher selectivity for dehydrogenation over hydrogenolysis than either pure metal.

High resolution electron microscopy of lanthanum phosphate crystals

1978 ◽  
Vol 36 (1) ◽  
pp. 274-275
Author(s):  
J. C. Wheatley ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
High Resolution ◽  
Petroleum Industry ◽  
High Resolution Electron Microscopy ◽  
Lanthanum Phosphate ◽  
Good Catalyst ◽  
Resolution Electron ◽  
Good Catalytic Activity ◽  
Physical And Chemical

Rare-earth phosphates are of particular interest because of their catalytic properties associated with the hydrolysis of many aromatic chlorides in the petroleum industry. Lanthanum phosphates (LaPO4) which have been doped with small amounts of copper have shown increased catalytic activity (1). However the physical and chemical characteristics of the samples leading to good catalytic activity are not known.Many catalysts are amorphous and thus do not easily lend themselves to methods of investigation which would include electron microscopy. However, the LaPO4, crystals are quite suitable samples for high resolution techniques.The samples used were obtained from William L. Kehl of Gulf Research and Development Company. The electron microscopy was carried out on a JEOL JEM-100B which had been modified for high resolution microscopy (2). Standard high resolution techniques were employed. Three different sample types were observed: 669A-1-5-7 (poor catalyst), H-L-2 (good catalyst) and 27-011 (good catalyst).

The design and catalytic performance of molybdenum active sites on an MCM-41 framework for the aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

2019 ◽  
Vol 9 (3) ◽  
pp. 811-821 ◽  
Author(s):  
Zhao-Meng Wang ◽  
Li-Juan Liu ◽  
Bo Xiang ◽  
Yue Wang ◽  
Ya-Jing Lyu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Aerobic Oxidation ◽  
Catalytic Performance ◽  
Mcm 41

The catalytic activity decreases as –(SiO)3Mo(OH)(O) > –(SiO)2Mo(O)2 > –(O)4–MoO.

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