Effect of analyzer scan time on the oxygen storage capacity performance in Pd-based TWCs
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Oxygen storage materials play an important role in increasing the performance of three-way catalysts. However, high operating temperatures and lubricant additives result in a reduction in the oxygen storage capacity (OSC), thus shortening the life of the catalyst. Therefore, it is important to measure and investigate OSCs using an appropriate protocol to evaluate catalyst’s performance and deactivation. In this study, the effect of analyzer scan time on the OSC performance of a commercial monolith three-way catalyst containing oxygen storage materials such as cerium-zirconium mixed oxide was investigated in a bench-flow reactor, and an appropriate scan time was suggested based on these results. This study also investigated OSC as a function of inlet gas temperatures between 300 and 550 °C. The results suggest that the OSC experiment should be performed using a scan time of at least 4.0 s, while reliable dynamic OSC results cannot be obtained if the analyzer scan time is longer than 4 s. Therefore, a study is required in order to determine the optimal OSC scan time to ensure accuracy, while also retaining an acceptable level of resolution. It was also confirmed that the OSC increases with increasing inlet gas temperature up to a temperature of 450 °C, but no longer increases above 450 °C.
Abstract
Oxygen storage materials play an important role in increasing the performance of three-way catalysts. However, high operating temperatures and lubricant additives result in a reduction in the oxygen storage capacity (OSC), thus shortening the life of the catalyst. Therefore, it is important to measure and investigate OSCs using an appropriate protocol to evaluate catalyst’s performance and deactivation. In this study, the effect of analyzer scan time on the OSC performance of a commercial monolith three-way catalyst containing oxygen storage materials such as cerium-zirconium mixed oxide was investigated in a bench-flow reactor, and an appropriate scan time was suggested based on these results. This study also investigated OSC as a function of inlet gas temperatures between 300 and 550 °C. The results suggest that the OSC experiment should be performed using a scan time of at least 4.0 s, while reliable dynamic OSC results cannot be obtained if the analyzer scan time is longer than 4 s. Therefore, a study is required in order to determine the optimal OSC scan time to ensure accuracy, while also retaining an acceptable level of resolution. It was also confirmed that the OSC increases with increasing inlet gas temperature up to a temperature of 450 °C, but no longer increases above 450 °C.
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