The aging impact on oxygen storage capacity (OSC) of three-way catalyst was investigated through experiments and modeling. OSC measurements were conducted on two commercial TWCs (one fresh and one aged) over the temperature window of 100–600 °C. The amount of OSC decreased by 44% at 400 °C and the kinetic restrictions of OSC reductions extended towards higher temperatures after standard bench cycle (SBC) aging at 955 °C for 57 h. The relationship between OSC and temperature was modified. Dynamic OSCs (breakthrough OSC and sub-surface OSC) on the fresh and aged TWCs were predicted with a dual-site OSC model. From the modeling results, we found that not only the quantities of oxygen storage sites decreased but also the qualities of storage sites (rate constants) declined after aging. The PGM and surface ceria interface (site S1) declined more severely compared to the sub-surface ceria (site S2). The change of the amount of oxygen storage sites as well as kinetics on the aged TWC sample are reported. From thermodynamic analysis, the alteration of the temperature dependence of OSC is attributed to the change of the thermodynamic properties of ceria.

通过实验和模型研究了老化对三效催化剂储氧量（OSC）的影响。OSC测量是在100-600°C的温度范围内，对两个商用TWC（一个新鲜的，一个老化的）进行的。在标准工作台循环（SBC）在955°C下老化57小时后，OSC的量在400°C时下降了44％，并且OSC下降的动力学限制向更高的温度延伸。修改了OSC与温度之间的关系。使用双站点OSC模型预测了新鲜和老化的TWC上的动态OSC（突破性OSC和地下OSC）。根据建模结果，我们发现不仅老化后氧气存储位置的数量减少，而且存储位置的质量（速率常数）也下降。与次表面二氧化铈（S2站点）相比，PGM和表面二氧化铈界面（S1站点）的下降更为严重。报告了老化的TWC样品上氧气存储位点数量的变化以及动力学。从热力学分析来看，OSC的温度依赖性的变化归因于二氧化铈热力学性质的变化。