ChemInform Abstract: THE ROLE OF GROUP VIII METAL PROMOTER IN MOLYBDENUM DISULFIDE AND TUNGSTEN DISULFIDE HYDROTREATING CATALYSTS. I. ESR STUDIES OF COBALT-MOLYBDENUM, NICKEL-MOLYBDENUM, AND NICKEL-TUNGSTEN CATALYSTS

1985 ◽  
Vol 16 (19) ◽  
Author(s):  
D. S. THAKUR ◽  
B. DELMON
Keyword(s):  
Molybdenum Disulfide ◽  
Tungsten Disulfide ◽  
Group Viii ◽  
Hydrotreating Catalysts ◽  
Group Viii Metal ◽  
Tungsten Catalysts ◽  
Nickel Tungsten ◽  
And Tungsten

Hydrogenolytic cleavage of pyridine on different cobalt-molybdenum and nickel-tungsten catalysts

1981 ◽  
Vol 46 (6) ◽  
pp. 1348-1354 ◽  
Author(s):  
Mirko Černý ◽  
Miloš Kraus
Keyword(s):  
Reaction Products ◽  
Hydrogenation Activity ◽  
Catalyst Composition ◽  
Tungsten Catalysts ◽  
Nickel Tungsten ◽  
And Tungsten

Composition of the reaction products formed by hydrogenation of pyridine at 300 °C and 15 MPa in the presence of 15 sulphided and unsulphided molybdenum and tungsten catalysts promoted by cobalt and by nickel, respectively, using alumina as the support in most cases, has been examined. It has been proved that the catalyst composition affects both its hydrogenation activity and the ratio of transalkylation to cracking (or hydrocracking) reactions. Relations between the catalyst composition and its activity and selectivity found for the reaction of pyridine differ from those reported for hydrogenolytic cleavage of thiophene, hydrogenation and isomerization of cyclohexene.

Tribological Studies of Transmission Oil Dispersed With Molybdenum Disulfide and Tungsten Disulfide Nanoparticles

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
V. Srinivas ◽  
R. N. Thakur ◽  
A. K. Jain ◽  
M. Saratchandra Babu
Keyword(s):  
Molybdenum Disulfide ◽  
Size Variation ◽  
Tungsten Disulfide ◽  
Particle Size Analyzer ◽  
Transmission Oil ◽  
Mos2 Nanoparticles ◽  
The Stability ◽  
Friction And Wear Characteristics ◽  
Load Conditions ◽  
And Tungsten

This paper compares the tribological properties of transmission oil dispersed with molybdenum disulfide (MoS2) and tungsten disulfide (WS2) nanoparticles. Lubricant samples are prepared by dispersing MoS2 and WS2 nanoparticles in 0.5 wt.% in transmission oil. The nanoparticles are stabilized in the lubricant by surface modification with surfactant SPAN 80. The stability of the lubricant in terms of size variation of dispersed nanoparticles is evaluated using particle size analyzer. The antiwear, antifriction, and extreme pressure (EP) properties are tested on a four-ball wear tester and a comparison is made to assess the relative performance of MoS2 and WS2 nanoparticles. The friction and wear characteristics of lubricant dispersed with nanoparticles are strongly dependent upon the load taken into consideration. The lubricant dispersed with WS2 nanoparticles gave higher weld load and load wear index (LWI) than that of lubricant dispersed with MoS2 nanoparticles. The metallographic studies show that under high load conditions, the WS2 nanoparticles deposit more than MoS2 nanoparticles, thereby giving better performance at higher load conditions.

Sign in / Sign up

Export Citation Format

Share Document