Tungsten disulfide catalysts

P. Kieran and C. Kemball [J. Catal., 4,394 (1965)] studied the reactions of thiophene (C4H4S) and hydrogen over a tungsten disulfide catalyst. The reaction network can be simplified to the following form ... 

Tungsten Disulfide and Molybdenum Disulfide. Arrhenius parameters reported for reactions on both these catalysts (222- 225) were close to two compensation lines, characteristic of cracking and exchange processes (Table II, O and P). Since the reactants studied in this work were different from those used in kinetic measurements on tungsten metal, no direct comparison of activities is appropriate. Data for reactions of thiophene did not correlate with either line. 

In normal vapor-phase operation the catalyst maintained its activity for 1 to 2 years, although some batches have been used for 5 years. The decrease in activity of the catalyst is caused by the irreversible absorption of high-molecular-weight hydrocarbons. Ash (e.g., iron phenolates) -containing feedstocks cause a more rapid loss of activity. Analyses of used catalysts indicated carbon contents of about 2%. Tungsten disulfide is isomorphous with molybdenum sulfide, and many of the catalytic properties of these two compounds are similar. X-ray analyses of the catalyst showed a hexagonal lattice (13). The primary size of the crystallites is about 3 X 10-7 cm. in height and twice that in width. Microscopic examinations showed that the crystals are pseudomorphous to the... 

Pig. 1. Adsorption of hydrogen on tungsten disulfide. I. Catalyst degassed at 300°C. II. Catalyst H2 treated and degassed at 300°C. 

Hydrogenation with Tungsten Disulfide as Catalyst Reaction without Change of the Carbon Skeleton... 

Use Source of high purity tungsten disulfide for catalysts, lubricants, semiconductors. 

Tungsten disulfide WS2 [10.8] is used for electrode activation in fuel cells. If produced by hydrogen reduction of (NH4)2WS4, it exhibits a BET surface 70 times larger than that of commercially prepared WS2. It acts as catalyst for the reaction... 

Inelastic neutron scattering has been applied since the early 1980s to characterise hydrogen and adsorbed species in the M0S2 catalysts [128]. Related catalysts, tungsten disulfide [129] and mthenium disulfide [130],... 

Catalysts for the vapor-phase step have to be sulfur-resistant and be able to convert sulfur-, oxygen-, and. nitrogen-containing compounds to hydrocarbons. A typical catalyst is 0.7 per cent molybdenum sulfide, 2 per cent chromium oxide, 5 per cent zinc oxide, and 10 per cent sulfur on fuller s earth. Tungsten disulfide is also a good catalyst. 

Tributylphosphine sulfide has been used as a co-catalyst with dicobalt octacarbonyl for the Pawson-Khand reaction. Thermolysis of a mixture of cadmium chloride and trioctylphosphine sulfide at 250 °C has been used as a route to the formation of nanocrystalline cadmium sulfide." A complex of triphenylphosphine sulfide with a silver-tungsten-iodine acceptor has been characterised by X-ray studies. Ferrocenylphosphine chalcogenides have attracted considerable interest as ligands. Complexes of the monophosphino-phosphine sulfide (269) with rhodium have been characterised." The disulfide (270) forms complexes with both gold(i) and gold(iii) acceptors," and a silver(i) complex of the diselenide (271) has been prepared. ... 

---