Hydrocarbon hydrogenation and catalyst therefor

A process for making a composition useful in selectively hydrogenating diolefins and alkynes to monoolefins, said process consisting essentially of the steps of:

• (i) contacting a material consisting essentially of
• at least one palladium-containing material selected from the group consisting of palladium metal and palladium oxides, and
• at least one inorganic support material, with a solution of at least one alkali metal iodide to obtain an alkali metal iodide-impregnated material,
• (ii) drying said alkali metal iodide-impregnated material to obtain a dried material, and
• (iii) heating said dried material in a non-oxidizing gas atmosphere at a temperature of about 300.degree. C. to about 600.degree. C. for a time period of about 0.2 hour to about 20 hours.

A process for making a composition useful in selectively hydrogenating diolefins and alkynes to monoolefins, said process comprising the steps of:

• (i) contacting a material consisting essentially of
• at least one palladium-containing material selected from the group consisting of palladium metal and palladium oxides, and
• at least one inorganic support material, with a solution of at least one alkali metal iodide to obtain an alkali metal iodide-impregnated material,
• (ii) drying said alkali metal iodide-impregnated material to obtain a dried material,
• (iii) heating said dried material in a non-oxidizing gas atmosphere at a temperature of about 300.degree. C. to about 600.degree. C. for a time period of about 0.2 hour to about 20 hours to obtain a heated material, and
• (iv) contacting said heated material with at least one sulfur-containing compound at a temperature of about 20.degree. C. to about 25.degree. C. for a time period of about 5 hours to about 20 hours.

A process for making a composition useful in selectively hydrogenating diolefins and alkynes to monoolefins, said process comprising the steps of:

• (i) contacting a material consisting essentially of
• at least one palladium-containing material selected from the group consisting of palladium metal and palladium oxides, and
• at least one inorganic support material, with a solution of at least one alkali metal iodate to obtain an alkali metal iodate-impregnated material,
• (ii) drying said alkali metal iodate-impregnated material to obtain a dried material, and
• (iii) heating said dried material in a reducing gas at a temperature of about 200.degree. C. to about 600.degree. C. for a time period of about 0.2 hour to about 20 hours, so as to convert said at least one alkali metal iodate to at least one alkali metal iodide.

A composition useful in selectively hydrogenating diolefins and alkynes to monoolefins consisting essentially of:

• about 0.05 weight-% palladium to about 1 weight-% palladium (on a total catalyst composition weight basis),
• about 0.05 weight-% potassium in potassium iodide to about 5 weight-% potassium in potassium iodide (on a total catalyst composition weight basis), and
• at least one inorganic support material selected from the group consisting of alumina, silica, titania, zirconia, aluminosilicates, zinc aluminate, zinc titanate, and combinations thereof, wherein
• at least about 50 weight-% of said palladium (on a palladium weight basis) is concentrated in an area within about 100 microns of the exterior surface of said composition, and
• said composition having been heated in a non-oxidizing gas atmosphere at a temperature of about 300.degree. C. to about 600.degree. C. for a time period of about 0.2 hour to about 20 hours.

A composition useful in selectively hydrogenating diolefins and alkynes to monoolefins consisting essentially of:

• about 0.05 weight-% palladium to about 1 weight-% palladium (on a total catalyst composition weight basis),
• about 0.05 weight-% potassium in potassium iodate to about 5 weight-% potassium in potassium iodate (on a total catalyst composition weight basis), and
• at least one inorganic support material selected from the group consisting of alumina, silica, titania, zirconia, aluminosilicates, zinc aluminate, zinc titanate, and combinations thereof, wherein
• at least about 50 weight-% of said palladium (on a palladium weight basis) is concentrated in an area within about 100 microns of the exterior surface of said composition, and
• said composition having been heated in a reducing gas atmosphere at a temperature of about 200.degree. C. to about 600.degree. C. for a time period of about 0.2 hour to about 20 hours, so as to convert said at least one alkali metal iodate to at least one alkali metal iodide.