以旋轉圓盤電極分析燃料電池中陽極觸媒受CO毒化之影響

Investigation for CO Tolerance of Anode Catalyst in Fuel Cell by Roating Disk Electrode

洪慧珊

指導教授 ： 林昇佃

元智大學/工程學院/化學工程與材料科學學系/碩士(2004年)

摘要

本實驗以旋轉圓盤電極測定不同結構的Pt觸媒對CO容忍度的影響，研究中比較以10％Pt/C、20％Pt/C與40％Pt/C（E-Tek）配製成的觸媒漿液在RDE上做CO容忍度的測試，作為發展以Pt為本質的抗CO毒化觸媒的參考依據。並測定自製雙金屬觸媒Pt-Ru/C與添加氧化物的Pt/WO3-C觸媒的CO容忍度特性。
實驗探討不同Pt/C觸媒在經過通入1小時1%CO（in N2）之後，對CO容忍度的影響，其中發現商用觸媒，表面所有的活性位置均被CO所佔據，且CO氧化峰的訊號增加量，約與H脫附訊號成1：1之關係。而在Pt-Ru/C方面，商用20% Pt-Ru（1：1）/C（J.M.）與自製10％Pt-Ru（1：1）/C，表面的活性位置則約有60％被CO所佔據，這表示Ru的功能包括降低CO在活性位置表面的吸附能力；不過自製 10％Pt-Ru（1：2）/C對CO吸附特性與Pt/C觸媒相似，表面所有的活性位置均被CO所佔據，顯示Pt/Ru比例對觸媒抗CO的能力有顯著影響。此外，動力學分析Pt表面對H2的電催化活性比對於CO的電催化活性高了一個數量級，反之Pt-Ru（1：1）/C觸媒對於CO的電催化活性比對H2的電催化活性高了約2倍，這也顯示添加Ru對抗CO毒化的能力的改善包括較佳的CO氧化活性。

關鍵字

RDE ； FC ； Pt catalyst

並列摘要

This study investigates the estimation of the parameters of electrochemistry, i.e., diffusion process in electrolyte solution, by RDE, and further study on kinetics of the surface of electrode.
In order to study the effect of CO tolerance on Pt catalyst, we used 10％Pt/C、20％Pt/C and 40％Pt/C (E-Tek）in RDE experiment. In addition, Pt-Ru/C and Pt/WO3-C catalysts are used for reference test.
By CO tolerance study on RDE experiment, we found that after 1%CO in N2 purge for 1hr, the commercial Pt/C catalyst was deactivated. The signal of CO oxidation increased and it is near the desorption signal of H. However, 20% Pt-Ru（1：1）/C（J.M.）and 10％Pt-Ru（1：1）/C catalysts show better CO tolerance, i.e, only 60% active sites occupied. This indicates that Ru lower the adsorption strength of CO. Like the commercial Pt/C catalyst, 10％Pt-Ru（1：2）/C shows the same deactivation. We propose that Pt and Ru divided into two atomic group during preparation, i.e., lower the resistance of CO by Ru. Besides, electrocatalytic activation of H2 is one order higher than that of CO, however, Pt-Ru（1：1）/C shows electrocatalytic activation of H2 half lower than that of CO. This indicates that CO tolerance of Ru may result from better CO oxidation.

並列關鍵字

HASH(0xc6bfeac)

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