Optimally catalyzed porous-silicon electrode of self-breathing micro fuel cells

Abstract

Pt nanoparticles (Pt-NPs) are deposited on porous-silicon surface by electrochemical reduction to form self-breathing electrode of micro proton-exchange-membrane fuel cells (μPEMFCs). The Pt-NPs modified porous-silicon self-breathing windows are integrated in the cathode flow-field plate to replace traditional carbon paper for enhancement air diffusion. The test results show that the peak current increases with increasing the loaded Pt-NPs and the maximum peak current is obtained at the Pt-NPs loading of 0.38 mg/cm2. Attributed to the high surface-area of the porous-silicon electrode, the Pt electro-catalytic performance is significantly enhanced compared to that by using the conventional carbon paper electrode where Pt/C was brushed with the similar Pt loading of 0.4 mg/cm2. Therefore, the μPEMFCs with the porous-silicon electrode show higher electric energy generation. Moreover, experiments show that the peak power-density of the fuel cell with 350 nm pore-sized porous-silicon electrode is 30 % higher than that with 5 μm-sized porous silicon.