Co-electroless deposition methods for formation of methanol fuel cell catalysts
The present disclosure is directed to compositions and structures of supported metal catalysts for use in applications such as direct methanol fuel cells. Generally, implementations include supported metal catalysts that include Pt active sites that have been modified by addition or co-localization of a second metal such as Cu, Co, Ni, and/or other base metals to lower the inhibiting effect of strongly-adsorbed CO, an intermediate of methanol oxidation. An example aspect of the present disclosure includes catalyst compositions where the exterior metal sites in the supported catalyst include at least two metals: Pt and a competitive binder (e.g., a second metal).
1. A fuel cell catalyst comprising:
a. a porous support; and
b. a plurality of metal particles deposited on the porous support,
wherein each of the metal particles comprises a core metal and a shell metal system, and wherein the shell metal system is deposited on the core metal, and wherein the shell metal system comprises Pt and a second metal, and wherein a ratio of Pt to the second metal is about 5:1 to about 0.15:1.
2. The fuel cell catalyst of claim 1 , wherein the porous support has a surface area in a range of about 10 m 2 /g to about 500 m 2 /g.
3. The fuel cell catalyst of claim 1 , wherein the porous support has a pore volume in a range of about 40 mm 3 /g and about 220 mm 3 /g.
4. The fuel cell catalyst of claim 1 , wherein the porous support has an average pore diameter in a range of about 10 nm to about 40 nm.
5. The fuel cell catalyst of claim 1 , wherein the porous support comprises boron nitride, titanium dioxide, silicon carbide, silicon nitride, or combinations thereof.
6. The fuel cell catalyst of claim 1 , wherein the second metal comprises one or more of: Co, Cu, Ni, Ag, Au, or combinations thereof.
7. The fuel cell catalyst of claim 1 , wherein the core metal comprises one or more of: Pd, Co, Cu, Ni, Ir, Rh, Mo, Fe, Pt, Re, Ru, W, or combinations thereof.
8. The fuel cell catalyst of claim 1 , wherein each of the metal particles comprise an alloy, and wherein the alloy includes a substantially homogenous distribution of the core metal and the shell metal system.
9. The fuel cell catalyst of claim 1 , wherein each of the metal particles are bimetallic, and wherein the core metal is Pd and the second metal comprises one of: Co, Cu, or Ni.
10. A methanol fuel cell comprising the fuel cell catalyst of claim 1 , wherein the methanol fuel cell displays has a mass activity of about 100 to about 400 A/g Pt .
11. The methanol fuel cell of claim 10 , wherein the second metal comprises Ni, and wherein the methanol fuel cell displays a mass activity of about 160 to about 200 A/g Pt .
12. The methanol fuel cell of claim 10 , wherein the second metal comprises Co, and wherein the methanol fuel cell displays a mass activity of about 160 to about 200 A/g Pt .
13. The methanol fuel cell of claim 10 , wherein the second metal comprises Co, and wherein the methanol fuel cell displays a mass activity of about 100 to about 400 A/g Pt .
14. The methanol fuel cell of claim 10 , further comprising a rotating disk electrode comprising the fuel cell catalyst.
15. The methanol fuel cell of claim 14 , further comprising an electrolyte solution comprising sulfuric acid.