Reaction kinetics at the nickel pattern electrode on YSZ and its dependence on temperature

The temperature change of reaction rate at the stripe-patterned nickel fuel electrodes on YSZ was examined by using complex impedance spectroscopy and a steady-state polarization current method, as functions of temperature and oxygen pressure in H{sub 2}O/H{sub 2} mixtures. By the analysis of {sigma}{sub E}, the electrode interface conductivity, and polarization current with the aid of reaction rate theory, it was shown that the reaction on the nickel pattern electrodes consists of the following three processes. First, an anodic reaction in which the rate is proportional to a{sub o}, P(H{sub 2}) and P(H{sub 2}O), where a{sub o} is the oxygen activity at the triple chase boundary. Second, the cathodic reaction rate is proportional to P(H{sub 2}O) and a{sub o}{sup {minus}1/2}. Third, the cathodic rate is proportional to P(H{sub 2}O) and a{sub o}{sup {minus}1} when temperature became higher or a{sub o} was very small.