| Summary: | 碩士 === 國立中央大學 === 機械工程學系 === 102 === Pulsed laser deposition (PLD) was used to prepare Pt nanoparticles on gas diffusion electrode by varying the Ar pressure in the dsposition chamber.
X-ray diffraction analysis and electrocatalytic activity of Pt nanoparticle indicate that the Ar pressure of 800 mTorr is the best operating point.The PLD catalysts was used at anode side of a polymer electrolyte membrane (PEM) fuel cell. With a Pt loading of 25 μg-Pt/cm2, current density
reaches 1366 mA/cm2 at 0.6 V, similar to commercial Pt/C at much higher Pt loading (200 μg-Pt/cm2). The mass specific power density(MSPD) increases about ten times as compared with commercial Pt/C. Even with lower Pt loading of 13 μg-Pt/cm2, the current density still have 1032 mA/cm2 .The
MSPD is 47.6 kW/g.
The primary reason that PLD catalysts show higher MSPD may be ascribed to reduced occurrence of island formation, which is common for traditional Pt/C catalysts.
TEM images indicate that the Pt nanoparticles have good dispersion. The size of the Pt nanoparticle is approximately 2-3 nm. Higher Pt loading causes Pt particles to aggregate. This is the main reason that MSPD decreases with increasing Pt loading. The electrochemical analysis found IV
electrochemical active surface area and ORR activity decrease with increasing platinum loading, due to Pt particle size increase and particle aggregation. In general, the trend of the electrochemical test result and fuel cell performance agree with each other.
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