Oxidation of Hydrogen Sulfide over Cobalt Molybdate and Related Catalysts

systems could favor the localization of tellurium either by means of interstitial or substitutional solid solution.The nature of the active sites in oxidative dehydrogenation of 1-butene to butadiene has also been discussed in terms of possible formation of Te==O groups or modification of M-0 groups previously present or even formation of Te==O M e 0 gem groups. AcknowledgmentsWe thank Professor I. Pasquon for encouragement and useful discussion and Italian Consiglio Nazionale delle Ricerche (Rome) for financial support. Literature CitedAbraham, S. C., Reddy, J. M., J. Chem. Phys., 43 (7), 2533 (1965). 413, 180 (1975).Cairati, L., Trifiro. F., Villa, P. L., Italian Patent 25 545 A 74 (July 25, 1974).Courtine, P.. Cord. P. P., Pannetier, G., Daumas, J. C., Montarnal, R., Bull. Soc. Fr., 4816 (1968).(1 966).(1 973). (1975).Received for reuieui M a r c h 16, 1976 Accepted November 14, 1976 The catalytic oxidation of H2S with O2 at 200 OC on various porous materials was investigated. The influence of the pore structure and the chemical composition of the materials on the activity and the selectivity toward the product (sulfur) was studied. It was found that in materials with an average pore diameter between 5 and 10 A the sulfur adsorption is strong. The catalytic activity per square meter of total surface area is approximately proportional to the amount of adsorbed sulfur. In this case the selectivity towardwdfur is high. In materials with larger pores sulfur adsorption is enhanced by the presence of Lewis acid sites and by a hydrophobic surface. For these materials the presence of water in the feed has an activity lowering effect. If iron oxide is present, at 200 OC, SO2 is the main product. This is the case when other group 6-8 metal ions are present. For practical use in an H2S removal process the industrial active charcoals, zeolite NaX, Ti02, and ZrOp are most suitable.

Section: Discussionmentioning

confidence: 98%

Section: Influence Of T H E Surface Composition Of Materialsmentioning

confidence: 99%

Catalytic Oxidation of Hydrogen Sulfide. Influence of Pore Structure and Chemical Composition of Various Porous Substances

Steijns¹,

Mars²

1977

“…On the other hand, considerable success has been achieved in the control of hydrogen sulfide since effluents containing large concentrations of this gas can be treated through the Claus reactions and various add-on processes (Davis, 1972). At low concentrations, catalytic oxidation (Ross and Jeanes, 1974) or absorption by alkaline suspensions of activated charcoal (Bhatia et al, 1975) removes >99% hydrogen sulfide from waste gases but alkaline suspensions of activated charcoal only remove 50 ± 30% of the organic sulfur compounds present (Bhatia et al, 1975).…”

Section: Introductionmentioning

confidence: 99%

Catalytic Oxidation of Methyl Mercaptan over Cobalt Molybdate

Ross¹,

Sood²

1977

Self Cite

mentioning

confidence: 95%

Adsorption of Hexachloroplatinic Acid on γ-Alumina

Santacesaria¹,

Carrà²,

Adami³

1977

the surface is an important factor for the meso-and macroporous materials. Generally the sulfur adsorption and activity are low as in the case of SiCL, MgO, and carbon blacks. The presence of Lewis acid sites of the surface of ALO;s and TiCL may enhance sulfur adsorption and thereby the activity. These acid sites can be poisoned with Lewis bases such as water or pyridine.Iron oxide shows exceptional behavior, because it combines a high activity with a very low selectivity. An oxidation-reduction mechanism involving the iron ion is very likely. Other investigators (Cook and Ross, 1973;Ross and Jeanes, 1974) found that the oxides of Co, Mo, Ni, and W also promote the direct conversion of HL> S in SCL.