A Study of CeSnO(x) and Pd/CeSnO(x) as Low-Temperature NO(x) Adsorbers with Excellent Hydrothermal Stability

[Image: see text] In the present work, we report on two passive NO(x) adsorber (PNA) material candidates: the novel support CeSnO(x) with and without Pd loading. The NO(x) adsorption and storage capacities of fresh and hydrothermally aged CeSnO(x) and Pd/CeSnO(x) were investigated. The results show that CeSnO(x) exhibits a rather large NO(x) uptake and storage capacity (28.9 μmol/g), while the loading of Pd on CeSnO(x) can further increase the storage capacity to 37.6 μmol/g and affect the desorption temperature of NO(x). It was found that the NO(x) desorption temperature of Pd/CeSnO(x) was compatible with the efficient operating window of selective catalytic reduction (SCR) catalysts. After a hydrothermal aging treatment at 800 °C for 12 h, the NO(x) adsorption and storage capacities of CeSnO(x) and Pd/CeSnO(x) increased, indicating excellent hydrothermal stability. The interaction of Pd with CeSnO(x), the state of Pd species, and the structure of CeSnO(x) and Pd/CeSnO(x) are studied by combination of the characterization results.