Low temperature NO_x adsorbers (LTNA) adsorb NO_x from diesel engines during cold starts and release the NO_x when the SCR system is operational. H₂O inhibited NO_x storage on Pd/CZO LTNAs below 100 °C, but above 100 °C C₂H₄ and H₂ increased the NO_x storage. CO improved the NO_x storage below 100 °C even with H₂O. Two potential mechanisms were identified for these improvements: (1) the reaction of NO and reductant to form intermediates on the LTNA; (2) partial reduction of some of the PdO_x. The different effects of C₂H₄, CO, and H₂ on the NO_x storage supported the first mechanism, as did the very rapid increase in NO_x slip when the reductant was turned off during a test. DRIFTS analysis confirmed NCO formation when NO and CO were fed to the sample at 100 °C. Based on CH₄ oxidation, NO alone or reductant alone did not reduce the PdO_x significantly during the first 5 min of the test, but significant reduction occurred with both NO and a reductant. This suggests that the NO and reductant interacted on the PdO_x, reducing the PdO_x in the process. Thus, the primary benefit of the reductants is to react with NO to form intermediates on the Pd/CZO LTNA.

低温NO _X吸附器（LTNA）吸附NO _X从在冷起动期间柴油发动机和释放NO _X时所述SCR系统是可操作的。ħ ₂ ö抑制NO _X在Pd存储/ CZO LTNAs低于100℃，但高于100℃C C ₂ ħ ₄和H ₂增加了NO _X存储。即使使用H ₂ O，CO也可将NO _x的储存量提高到100°C以下。为这些改进确定了两个潜在的机制：（1）NO和还原剂在LTNA上形成中间体的反应；（2）部分还原某些PdO _x。C ₂的不同作用NO _x存储中的H ₄，CO和H ₂支持第一种机理，在测试过程中关闭还原剂时，NO _x泄漏非常迅速地增加。当在100°C下将NO和CO送入样品时，DRIFTS分析证实了NCO的形成。基于CH _4的氧化作用，在测试的前5分钟内，单独使用NO或单独使用还原剂并不会显着降低PdO _x，但是使用NO和还原剂均会显着降低PdO _x。这表明NO和还原剂在PdO _x上相互作用，从而还原了PdO _x进行中。因此，还原剂的主要好处是与NO反应，在Pd / CZO LTNA上形成中间体。