A Study of CeSnOx and Pd/CeSnOx as Low-Temperature NOx Adsorbers with Excellent Hydrothermal Stability

Shasha Huang; Yulong Shan; Xiaoyan Shi; Zhongqi Liu; Qiang Wang; Hong He

doi:10.1021/acsomega.3c00841

A Study of CeSnO_x and Pd/CeSnO_x as Low-Temperature NO_x Adsorbers with Excellent Hydrothermal Stability

ACS Omega. 2023 Aug 16;8(34):30859-30867. doi: 10.1021/acsomega.3c00841. eCollection 2023 Aug 29.

Authors

Shasha Huang^{1

2

3}, Yulong Shan^{1

4}, Xiaoyan Shi^{1

4}, Zhongqi Liu^{1

4}, Qiang Wang^{2

3}, Hong He^{1

4

5}

Affiliations

¹ State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
² Beijing Key Lab for Source Control Technology of Water Pollution, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
³ Engineering Research Center for Water Pollution Source Control & Eco-remediation, College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, China.
⁴ University of Chinese Academy of Sciences, Beijing 100049, China.
⁵ Center for Excellence in Regional Atmospheric Environment. Institute of Urban Environment. Chinese Academy of Sciences, Xiamen 361021, China.

Abstract

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.