Modified carbide and oxycarbide containing catalysts and methods of making and using thereof
View Patent ↗Compositions including modified carbide-containing nanorods and/or modified oxycarbide-containing nanorods and/or modified carbon nanotubes bearing carbides and oxycarbides and methods of making the same are provided. Rigid porous structures including modified oxycarbide-containing nanorods and/or modified carbide containing nanorods and/or modified carbon nanotubes bearing modified carbides and oxycarbides and methods of making the same are also provided. The compositions and rigid porous structures of the invention can be used either as catalyst and/or catalyst supports in fluid phase catalytic chemical reactions. Processes for making supported catalyst for selected fluid phase catalytic reactions are also provided.
1. A method for the isomerization of a hydrocarbon comprising the step of: contacting a feed stream including a hydrocarbon under isomerization conditions with a composition, said composition including a plurality of nanostructures selected from the group consisting of carbon nanotubes, carbide nanorods, and mixtures thereof, each having a substantially uniform diameter between 1 nm and 100 nm and a length to diameter ratio greater than 5, said nanostructures further including a metal carbide selected from the group consisting of carbides and oxycarbides of a transition metal, rare earth metal or actinide, said composition having an ammonia desorption peak at a temperature greater than 100° C.
2. The method of claim 1 , wherein said hydrocarbon is selected from the group consisting of normal, branched, and cyclic hydrocarbons.
3. The method of claim 1 , wherein said hydrocarbon is an alkene.
4. The method of claim 1 , wherein said isomerization conditions include a temperature from 100° C. to 400° C., a molar ratio of hydrocarbon to hydrogen of 1:16 to 1:4, a pressure from about 1 to 10 psi, and a WHSV from 1 to 10 h −1 .
5. A method for the isomerization of a hydrocarbon comprising the step of: contacting a feed stream including a hydrocarbon under isomerization conditions with a composition, said composition including a plurality of nanostructures selected from the group consisting of carbon nanotubes, carbide nanorods, and mixtures thereof, each having a substantially uniform diameter between 1 nm and 100 nm and a length to diameter ratio greater than 5, said nanostructures further including a metal carbide selected from the group consisting of carbides and oxycarbides of a transition metal, rare earth metal or actinide, said nanotubes having been modified by an acidification treatment.
6. The method of claim 5 , wherein said hydrocarbon is selected from the group consisting of normal, branched, and cyclic hydrocarbons.
7. The method of claim 5 , wherein said hydrocarbon is an alkene.
8. The method of claim 5 , wherein said isomerization conditions include a temperature from 100° C. to 400° C., a molar ratio of hydrocarbon to hydrogen of 1:16 to 1:4, a pressure from about 1 to 10 psi, and a WHSV from 1 to 10 h −1 .
9. The method of claim 5 , wherein said acidification treatment is treatment with an acidifying compound.
10. The method of claim 9 , wherein said acidification treatment is selected from the group consisting of halogenation, chlorination, nitrogenation, oxygenation, and phosphorylation.
11. A method for the isomerization of a hydrocarbon comprising the step of: contacting a feed stream including a hydrocarbon under isomerization conditions with a composition, said composition including: (a) a rigid porous structure formed from a plurality of nanostructures selected from the group consisting of carbon nanotubes, carbide nanorods, and mixtures thereof, each having a substantially uniform diameter between 1 nm and 100 nm and a length to diameter ratio greater than 5, said nanostructures further including a metal carbide selected from the group consisting of carbides and oxycarbides of a transition metal, rare earth metal or actinide, said rigid porous structure including a plurality of interstitial spaces between said nanostructures; and (b) a solid acid in said interstitial spaces.
12. The method of claim 11 , wherein said hydrocarbon is selected from the group consisting of normal, branched, and cyclic hydrocarbons.
13. The method of claim 11 , wherein said hydrocarbon is an alkene.
14. The method of claim 11 , wherein said isomerization conditions include a temperature from 100° C. to 400° C., a molar ratio of hydrocarbon to hydrogen of 1:16 to 1:4, a pressure from about 1 to 10 psi, and a WHSV from 1 to 10 h −1 .
15. The method of claim 11 , wherein said solid acid is a compound containing an element selected from the group consisting of aluminum and zirconium.
16. The method of claim 15 , wherein said solid acid is a compound containing aluminum and the solid acid has been chlorinated, sulfated, or phosphated.
17. The method of claim 15 , wherein said solid acid is a compound containing zirconium and the solid acid has been chlorinated, sulfated, or phosphated.
18. The method of claim 11 , wherein said rigid porous structure has a density greater than about 0.5 gm/cm 3 and a porosity greater than about 0.8 cc/gm.
19. The method of claim 18 , wherein said rigid porous structure is substantially free of micropores and has a crush strength greater than about 1 lb/in 2 .