Metal-carbon composite powders
Metal-carbon composite powders and methods for producing metal-carbon composite powders. The powders have a well-controlled microstructure and morphology and preferably have a small average particle size. The method includes forming the particles from an aerosol of powder precursors. The invention also includes novel devices and products formed from the composite powders.
1. A dry powder batch of metal-carbon composite particles comprising at least about 3 weight percent of a carbon phase and a metal phase, wherein said metal phase is dispersed on said carbon phase, and wherein said particles have an average particle size of not greater than about 20 μm and wherein said particles have not been subjected to milling.
2. A powder batch as recited in claim 1 , wherein said average particle size is greater than about 1 μm.
3. A powder batch as recited in claim 1 , wherein said average particle size is not greater than about 10 μm.
4. A powder batch as recited in claim 1 , wherein said particles are substantially spherical.
5. A powder batch as recited in claim 1 , wherein said particles have a size distribution wherein at least about 80 weight percent of said particles are not greater than about 2 times the average particle size.
6. A powder batch as recited in claim 1 , wherein said particles have a size distribution wherein at least about 90 weight percent of said particles are not greater than about 2 times the average particle size.
7. A powder batch as recited in claim 1 , wherein said particles have an impurity content of not greater than about 0.1 atomic percent.
8. A powder batch as recited in claim 1 , wherein said particles have a surface area of at least about 50 m 2 /g.
9. A powder batch as recited in claim 1 , wherein said particles have a surface area of from about 50 m 2 /g to 500 m 2 /g.
10. A powder batch as recited in claim 1 , wherein said carbon phase comprises carbon particles having a surface modified with amine groups.
11. A powder batch as recited in claim 1 , wherein said carbon phase comprises particulate carbon having an average size of from about 5 to about 100 nanometers.
12. A powder batch as recited in claim 1 , wherein said particles comprise at least about 50 weight percent carbon.
13. A powder batch as recited in claim 1 , wherein said powder batch comprises no more than about 1 weight percent hard agglomerates.
14. A powder batch as recited in claim 1 , wherein said metal phase comprises platinum.
15. A powder batch as recited in claim 1 , wherein said metal phase has an average crystallite size is less than about 50 nanometers.