Kinetics of Hydrogen Oxidation Reaction on Nafion-coated Pt/C Electrodes under High Overpotentials

Nafion覆蓋Pt/C電極在高過電位下氫氣氧化反應的動力學

林仁斌(Ren-Bin Lin) ； 施信民(Shin-Min Shih)

《Journal of the Chinese Institute of Chemical Engineers》 38卷5&6期 (2007/11) Pp. 365-370

摘要

本研究以旋轉電極探討浸沒在0.5M硫酸液中的Nafion覆蓋20wt% Pt/C電極之Nafion膜厚與鉑黑負載量對氫氣氧化反應動力學的影響。Nafion膜的厚度(≦8μm)對表面積量測幾無影響。在高過電位(0.4V)下所估算的動力學參數因鞽數據處理方法以而有所不同。Nafion膜厚度小於0.2μm時，膜內的氫氣質傳阻力可以忽略。氫氣在Nafion膜中的滲透係數介於2.4×10^(-5)~4.8×10^(-5) mM 平方公分/s之間。誤差分析顯示所估算的視動力電流是由於實驗誤差所致，而非如先前研究者所提出是由於化學程式所致。

並列摘要

The influences of the Nafion film thickness and Pt loading on the kinetics of the hydrogen oxidation reaction on Nation-Coated 20 wt% Pt/C electrodes immersed in 0.5 M H2SO4 were investigated using a rotating disk electrode configuration. The coating of a Nafion film (≦8μm) had a negligible effect on the electrochemical surface area of an electrode. The kinetic parameters were estimated at an overpotential of 0.4V; the values obtained were shown to vary with the method of data treatment. The diffusional resistance for H2 in the Nafion film was negligible when the film was thinner than 0.2μm. The permeability of H2 in the Nafion film ranged from 2.4×10^(-5)to 4.8×10^(-5)mM cm^2s. The error analysis demonstrated that the apparent kinetic current estimated was resulted from experimental errors, instead of resulting from a chemical process as proposed by some previous investigators.

並列關鍵字

Platinum on carbon ； Nafion ； Rotating disk electrode ； Hydrogen oxidation ； Fuel cells