Structurally ordered nanoparticles, methods and applications
Embodiments provide a nanoparticle and a method for preparing the nanoparticle, as well as a membrane that includes the nanoparticle and a fuel cell that includes the membrane. The method comprises a thermal treatment method that provides from a nanoparticle comprising a structurally disordered material the nanoparticle comprising: (1) a structurally ordered core comprising a first material; and (2) a shell surrounding and further structurally aligned with the structurally ordered core and comprising a second material different from the first material. Particularly desirable is a nanoparticle comprising a Pt 3 Co@Pt/C structurally ordered core-shell composition supported upon a carbon support.
1. A nanoparticle comprising:
a core comprising a first material arranged in a structurally ordered array, the core comprising a Pt x Co y intermetallic material; and
a shell surrounding the core and comprising a second material different from the first material and further structurally ordered with respect to the structurally ordered array;
wherein the nanoparticle is substantially free of (211) X-ray diffraction peaks.
2. The nanoparticle of claim 1 wherein a lattice parameter of the structurally ordered array is no greater than about 0.3915 nanometers.
3. The nanoparticle of claim 1 further comprising a carbon carrier for the nanoparticle.
4. The nanoparticle of claim 1 , wherein x and y each range from 1 to 10.
5. The nanoparticle of claim 1 , wherein the nanoparticle shell comprises more than one layer.
6. The nanoparticle of claim 5 , wherein the shell layer comprises 2-3 atomic layers of the second material.
7. The nanoparticle of claim 1 , wherein one or more experimentally-derived X-ray diffraction peaks for the nanoparticle match X-ray diffraction peaks found in a Powder Diffraction File (PDF) for a pure sample of the first material.
8. The nanoparticle of claim 1 , wherein a lattice parameter of the structurally ordered array is no greater than about 0.3845 nanometers.
9. A membrane comprising:
a nanoparticle comprising:
a core comprising a first material arranged in a structurally ordered array, the core comprising a Pt x Co y intermetallic material; and
a shell surrounding the core and comprising a second material different from the first material and further structurally ordered with respect to the structurally ordered array;
wherein the nanoparticle is substantially free of (211) X-ray diffraction peaks.
10. The membrane of claim 9 wherein a lattice parameter of the structurally ordered array is no greater than about 0.3915 nanometers.
11. The membrane of claim 9 , wherein x and y each range from 1 to 10.
12. The membrane of claim 9 , wherein the nanoparticle shell comprises more than one layer.
13. A fuel cell comprising:
a membrane comprising a nanoparticle comprising:
a core comprising a first material arranged in a structurally ordered array, the core comprising a Pt x Co y intermetallic material; and
a shell surrounding the core and comprising a second material different from the first material and further structurally arranged with respect to the structurally ordered array;
wherein the nanoparticle is substantially free of (211) X-ray diffraction peaks.
14. The fuel cell of claim 13 wherein a lattice parameter of the structurally ordered array is no greater than about 0.3915 nanometers.
15. The fuel cell of claim 13 , wherein x and y each range from 1 to 10.
16. The fuel cell of claim 13 , wherein the nanoparticle shell comprises more than one layer.
17. A nanoparticle comprising:
a core comprising a first material arranged in a structurally ordered array, the core comprising a M1 x M2 y intermetallic material, where:
M1 includes at least one metal selected from the group consisting of Ru, Rh, Pd, Os, and Ir, and Pt; and
M2 includes at least one metal selected from the group consisting of Mn, Fe, Co, Ni, and Cu; and
a shell surrounding the core and comprising a second material different from the first material and further structurally ordered with respect to the structurally ordered array;
wherein the nanoparticle is substantially free of (211) X-ray diffraction peaks and comprises a (220) X-ray diffraction peak at about 69-70 degrees.
18. The nanoparticle of claim 17 , wherein one or more experimentally-derived X-ray diffraction peaks for the nanoparticle match X-ray diffraction peaks found in a Powder Diffraction File (PDF) for a pure sample of the first material.