旋转圆盘电极（RDE）体系主要用于低溶解度反应物的电极过程动力学研究. 在利用RDE技术研究不可逆电极反应动力学时，人们常利用Koutecky-Levich方程排除传质的影响，从总电流估算反应的动力学电流. 由于K-L方程是建立在系统满足稳态扩散模型的基础上，实际运用时如果体系偏离稳态扩散，就有可能对估算的动力学参数造成很大误差. 本文以氧气在多晶铂电极上的还原反应为例系统地估算了不同氧气浓度与电极转速下的误差，结果表明低氧气浓度与低圆盘转速的情况不满足稳态扩散条件，若此时仍根据K-L方程利用外推法进行分析，误差可达30%. 因此作者建议，在RDE体系中利用K-L方程估算动力学参数时，最好忽略低浓度与低转速下的数据，直接使用较高浓度与较高转速下的数据进行计算与分析.

Rotating disk electrode system is mainly used to study the kinetics of reactions whose reactants have very low solubility in the electrolyte. For an irreversible reaction, Koutecky-Levich equation (K-L Eq.) is frequently used to deduce the kinetic current i_k). Since K-L Eq. is derived based on the assumption that a system should conform the steady-state diffusion conditions, the data recoded from the actual system which deviates from such a condition, great error may be induced for the i_k estimated. In this work, polarization curves for oxygen reduction reaction at polycrystalline Pt electrode recorded in solutions with various O₂ concentrations and under various electrode rotation speeds have been analyzed systematically. Our analysis reveals that an error of 30% may be introduced by extrapolation to infinite rotation speed in solution with low O₂ concentration or by including the data recorded under very slow electrode rotation speeds. The origins of the error and the ways to avoid such error are discussed.