Pd-Pt Catalyst Layer Formation Based on Porous Si

Our group proposed a Si based miniature fuel cell that has both fuel channel and catalyst layer on a Si substrate[1]. Maximum power density reached 500 mW/cm² at 313 K with H₂-O₂ supply, which is comparable to conventional state-of-the-art fuel cells. In the fabrication process, initially porous Si is formed by anodization in a HF solution, then the Si is replaced by Pt in a wet plating process, and a porous Pt catalyst layer is formed on a Si chip. The catalyst layer consists of Pt, and amount Pt is estimated to be 3.6 mg/cm², while typical conventional fuel cells use only 0.1 mg/cm². We have to reduce the amount of Pt for practical use of the miniature fuel cell. 
We found that porous Pd layer can be also made with almost identical process to the porous Pt formation, and have discussed Pd-Pt catalyst for reduction of the Pt usage in our miniature fuel cells. In this study, slight Pt was deposited on the porous Pd, and prototype fuel cells showed increase of power output by only 0.01mg/cm²Pt deposition. Furthermore, the Pd-Pt catalyst showed promissing result to CO poisoning.

[1] M. Hayase, T. Fujii, J. G. A. Brito-Neto, J. Electrochem. Soc., 158(4), B355-359 (2011)