Catalysts that include a fibrous silica support and metal oxide nanoparticles and methods of making and using same
The disclosure relates to catalysts that include a fibrous silica support and a plurality of metal oxide nanoparticles including iron oxide and nickel oxide, and methods of making and using such catalysts. The fibrous silica support is a particle with radially extending fibers. The catalyst can used to convert methane into hydrogen gas. The catalysts can be introduced into an underground formation, such as with a fracking fluid, for in-situ methane conversion.
1. A catalyst, comprising:
a fibrous silica support comprising a particle with radially extending fibers; and
a plurality of metal oxide nanoparticles supported by the fibrous silica support,
wherein the plurality of metal oxide nanoparticles comprise iron oxide (Fe 2 O 3 ) and nickel oxide (NiO); and
wherein the metal oxide nanoparticles have a diameter of 20 nm to 50 nm.
2. The catalyst of claim 1 , wherein the catalyst comprises from 4 wt. % to 15 wt. % iron oxide.
3. The catalyst of claim 1 , wherein the catalyst comprises from 4 wt. % to 30 wt. % nickel oxide.
4. The catalyst of claim 1 , wherein the catalyst comprises from 80 wt. % to 90 wt. % of the fibrous silica support.
5. The catalyst of claim 1 , wherein the particle of the fibrous silica support has a maximum linear dimension of 80 nm to 200 nm.
6. The catalyst of claim 1 , wherein the catalyst has a surface area of from 200 square meters per gram (m 2 /g) to 550 m 2 /g.
7. The catalyst of claim 1 , wherein at least one of the following characteristics holds for at least a portion of the fibrous silica support:
the fibrous silica support comprises an external surface and at least some of the metal oxide nanoparticles are supported on the external surface; or
the metal oxide nanoparticles are disposed in spaces between fibers of the fibrous silica support.
8. The catalyst of claim 1 , wherein the metal oxide nanoparticles comprise cesium oxide.
9. The catalyst of claim 8 , wherein the catalyst comprises 0.02 wt. % to 1 wt. % cesium oxide.
10. A method of converting methane to hydrogen gas, using the catalyst as defined by claim 1 .
11. The method of claim 10 , wherein the catalyst has a methane conversion of 10% to 40%.
12. The method of claim 10 , wherein the catalyst has a hydrogen yield of 35% to 70%.
13. A method comprising:
disposing the catalyst of claim 1 into an underground formation comprising methane; and
converting at least a portion of the methane in the underground formation into hydrogen gas.
14. The method of claim 13 , further comprising, producing the hydrogen gas from the underground formation.
15. The method of claim 13 , wherein the disposing further comprises:
forming a fluid comprising the catalyst; and
disposing the fluid into the underground formation.
16. The method of claim 15 , wherein the fluid comprises a fracturing fluid, and disposing the fluid in the underground formation forms fractures in the underground formation.
17. The method of claim 13 , wherein the converting comprises forming carbon dioxide.
18. The method of claim 17 , wherein at least one of the following holds:
the method further comprises using the carbon dioxide for fine fracture development; or
the method further comprises using the carbon dioxide to displace a liquid within the underground formation.
19. The catalyst of claim 1 , wherein the metal oxide nanoparticles further comprise a member selected from the group consisting of Fe, Fe 3 O 4 , and Ni.