Activation of Pd/SSZ-13 in Low Temperature NO Adsorption for Cold Start Application

As the regulation on NOx emission in exhaust gas has been globally issued and enforced, the purification of NOx from diesel engine is regarded as a great challenge. Although selective catalytic reduction (SCR) catalyst effectively reduce NOx in exhaust gas, this system cannot operate properly below 200 °C (i.e. during cold start period, initial ca. 100 – 200 sec of engine operation). Therefore, during the warm-up of NOx reduction catalyst, the considerable amount of NOx is emitted into atmosphere without any treatment [1]. Recently, cold start NOx trap catalysts attract significant attention with a concept of storing NOx at low temperature (i.e. during cold start) and releasing them at elevated temperature, where SCR operates. In this work, we tried to apply various Pd/SSZ-13 catalysts with different Pd loading method and investigate the effects of hydrothermal aging (HTA) treatment on the NOx adsorption ability and the physicochemical change of Pd/SSZ-13.