Kinetics of the electrode reaction at the H[sub 2]-H[sub 2]O porous Pt/stabilized zirconia interface
Kinetics of the electrode reaction at the H[sub 2]-H[sub 2]O porous Pt/stabilized zirconia interface
复制标题
H[sub 2]-H[sub 2]O多孔Pt/稳定氧化锆界面电极反应动力学
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
K. Hirano
中科院分区：
文献类型：
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作者：
J. Mizusaki;H. Tagawa;Kensuke Isobe;Motoaki Tajika;Ikumasa Koshiro;Hideki Maruyama;K. Hirano
近年来，人们对多孔Pt/稳定氧化锆界面在化合物-气体混合物如CO-CO[sub 2]、H[sub 2]-H[sub 2]O、CH[sub 4]-H[sub 2]O等中的电极反应非常感兴趣，因为该反应作为氧化锆电池中电极反应的模型对于传感器、燃料电池、水电解槽或其它应用是重要的。为了阐明在H[sub 2]-H[sub 2]O多孔Pt/稳定氧化锆界面处的电极反应机理，对电极界面电导率[sigma][sub E]和稳态极化电流I进行测量，所述电极界面电导率[sigma][sub E]和稳态极化电流I作为H[sub 2]分压p[sub H2]和H[sub 2]O分压p[sub H2O]的函数，直到800 ℃。在700 ~ 800 ℃下，H[sub 2]-H[sub 2]O气氛中的电极反应速率比CO-CO[sub 2]气氛中的快，比富O[sub 2]气氛中的慢1 ~ 2个数量级。速率控制反应过程是在气体/Pt/稳定氧化锆的三相边界（TPB）处Pt-和稳定氧化锆表面之间吸附的OH自由基的交换。
Recently, much interest has been focused on the electrode reaction at the interface of porous Pt/stabilized zirconia in compound-gas mixtures such as CO-CO[sub 2], H[sub 2]-H[sub 2]O, CH[sub 4]-H[sub 2]O, and others, because this reaction is important as a model of the electrode reaction in zirconia cells either for sensors, fuel cells, water electrolyzer, or other applications. To elucidate the mechanism of the electrode reaction at the interface of H[sub 2]-H[sub 2]O porous Pt/stabilized zirconia, measurements were made on the electrode interface conductivity, [sigma][sub E], and the steady-state polarization current, I, as a function of H[sub 2] partial pressure, p[sub H2], and H[sub 2]O partial pressure, p[sub H2O], up to 800 C. The rate of the electrode reaction at 700 to 800 C in H[sub 2]-H[sub 2]O atmospheres is faster than that in CO-CO[sub 2] and slower than that in O[sub 2] rich atmospheres by 1 to 2 orders of magnitude. The rate-determining reaction process was the exchange of adsorbed OH radicals between the Pt- and the stabilized zirconia-surface at the triple-phase boundary (TPB) of gas/Pt/stabilized zirconia.