Song Kunli, Zhao Shuqi, Li Zhenguo, Li Kaixiang, Xu Yurong, Zhang Yijun, Cheng Yonghong, Shi Jian-Wen
State Key Laboratory of Electrical Insulation and Power Equipment, Center of Nanomaterials for Renewable Energy, School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
National Engineering Laboratory for Mobile Source Emission Control Technology, China Automotive Technology and Research Center Co. Ltd, Tianjin 300300, China.
J Colloid Interface Sci. 2023 Jan;629(Pt A):243-255. doi: 10.1016/j.jcis.2022.08.174. Epub 2022 Sep 5.
SSZ-13 has been commercialized as a catalyst in diesel engines for the selectivity catalytic reduction of nitrogen oxides (NO) with ammonia (NH-SCR), but the catalyst is facing the problem of poisoning. Herein, two well-designed catalysts, Cu-SSZ-13 and cerium (Ce) doped Cu-SSZ-13 are synthesized, and their tolerance to zinc (Zn) and phosphorus (P) poisoning alone and together are explored in detail. The research found that Zn and P poisoning alone leads to the destruction of Cu-SSZ-13 structure, resulting in the decline of denitration (de-NO) performance following the mechanism dominated by Eley-Rideal (E-R). Surprisingly, it is found that zinc phosphate particles are formed at inactive sites on the surface of Cu-SSZ-13 in the presence of Zn and P together, which protects the active sites, enhances the adsorption of nitric oxide. As a result, the excellent de-NO performance of Cu-SSZ-13 is well maintained following the dual mechanism of E-R and Langmuir-Hinshelwood (L-H). In addition, the introduction of Ce stabilizes the active sites, so as to improve the de-NO performance and the poisoning tolerance of Cu-SSZ-13. This work deeply analyzes the reasons of Zn and P poisoning and the positive effect of Ce on Cu-SSZ-13, which provides ideas for improving the poisoning tolerance of Cu-SSZ-13 and promotes the further application.
SSZ-13已作为一种催化剂商业化应用于柴油发动机中，用于氨选择性催化还原氮氧化物（NO）（NH-SCR），但该催化剂面临中毒问题。在此，合成了两种精心设计的催化剂，即铜掺杂的SSZ-13（Cu-SSZ-13）和铈（Ce）掺杂的Cu-SSZ-13，并详细探究了它们单独以及共同对锌（Zn）和磷（P）中毒的耐受性。研究发现，单独的Zn和P中毒会导致Cu-SSZ-13结构破坏，按照以Eley-Rideal（E-R）为主导的机理，导致脱硝（de-NO）性能下降。令人惊讶的是，发现在同时存在Zn和P的情况下，Cu-SSZ-13表面的非活性位点会形成磷酸锌颗粒，这些颗粒保护了活性位点，增强了一氧化氮的吸附。结果，按照E-R和Langmuir-Hinshelwood（L-H）的双重机理，Cu-SSZ-13优异的de-NO性能得以很好地保持。此外，Ce的引入稳定了活性位点，从而提高了Cu-SSZ-13的de-NO性能和中毒耐受性。这项工作深入分析了Zn和P中毒的原因以及Ce对Cu-SSZ-13的积极作用，为提高Cu-SSZ-13的中毒耐受性提供了思路，并促进了其进一步应用。
