Tang Xuan, Gao Yanzhao, Li Wenbo, Dai Sheng, Wang Li, Guo Yun, Guo Yanglong, Zhan Wangcheng, Wang Aiyong
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China.
Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China.
Environ Sci Technol. 2025 Jul 8;59(26):13447-13457. doi: 10.1021/acs.est.5c01029. Epub 2025 Jun 25.
The SSZ-13 zeolite-supported Cu (Cu/SSZ-13) is a commercial catalyst for ammonia selective catalytic reduction (NH-SCR), but it faces challenges such as phosphorus poisoning in practical applications. Despite extensive investigations into how phosphorus poisoning leads to the deactivation of Cu/SSZ-13, effective strategies for regenerating catalysts with high phosphorus loading poisoned under practical conditions remain underdeveloped. In this study, we propose that incorporating Mg ions into Cu/SSZ-13 zeolites can significantly enhance their resistance and regeneration ability against phosphorus poisoning. After hydrothermal aging at 650 °C, the NH-SCR activity of phosphorus-poisoned Cu/SSZ-13 catalysts with high phosphorus loading (0.6 mmol/g) cannot be effectively restored; however, the addition of Mg enables nearly complete recovery of their activity. Combining advanced microscopy evidence with complementary spectroscopy results, we reveal that Mg ions occupy the Brønsted acid sites in the six-membered rings (6-MRs) of SSZ-13, which regulates the distribution of subsequently introduced Cu ions while enhancing the stability of Cu and the framework Al of SSZ-13, inhibiting the aggregation of Cu species after phosphorus poisoning and thereby improving resistance. Furthermore, the preservation of the SSZ-13 framework also effectively facilitates the redispersion of Cu species after hydrothermal aging, significantly restoring NH-SCR performance.
SSZ-13分子筛负载的铜（Cu/SSZ-13）是一种用于氨选择性催化还原（NH-SCR）的商业催化剂，但在实际应用中面临着诸如磷中毒等挑战。尽管对磷中毒如何导致Cu/SSZ-13失活进行了广泛研究，但针对在实际条件下中毒的高磷负载催化剂的有效再生策略仍未得到充分发展。在本研究中，我们提出将镁离子引入Cu/SSZ-13分子筛可显著提高其抗磷中毒能力和再生能力。在650℃水热老化后，高磷负载（0.6 mmol/g）的磷中毒Cu/SSZ-13催化剂的NH-SCR活性无法有效恢复；然而，添加镁能使其活性几乎完全恢复。结合先进的显微镜证据和互补的光谱结果，我们发现镁离子占据了SSZ-13六元环（6-MRs）中的布朗斯台德酸位点，这在调节随后引入的铜离子分布的同时，增强了Cu和SSZ-13骨架Al的稳定性，抑制了磷中毒后Cu物种的聚集，从而提高了抗性。此外，SSZ-13骨架的保留也有效地促进了水热老化后Cu物种的再分散，显著恢复了NH-SCR性能。
