Insight into the effect of phosphorus poisoning of Cu/zeolites with different framework towards NH3-SCR

Cu/zeolites were prepared to elucidate the effect of phosphorus poisoning on different zeolite framework structures for NH3-SCR. The results show that there are significant differences in phosphorus poisoning depending on the zeolite framework structure. The PO3-/PO43- species gradually decreased along with an increase in P2O5 in the following order: Cu/SSZ-13, Cu/ZSM-5, and Cu/BEA. One possible reason could be the increased pore size of these zeolites, which results in less steric hindrance for larger P2O5 species. P2O5 is suggested to enhance the redox ability of Cu ions, which results in an increase in low-temperature activity in NH3-SCR, whereas Cu ions were significantly poisoned by PO3-/PO43-, resulting in low-temperature deactivation. Furthermore, the effect of phosphorus poisoning on the structure of Cu/ZSM-5 was found to be much greater than that of Cu/BEA and Cu/SSZ-13, possibly due to phosphorus attacked the surface defects of the zeolite, causing local expansion and cracking.

Automated summary

Cu/zeolites were prepared to study the effect of phosphorus poisoning on different zeolite framework structures for NH3-SCR. The results showed significant differences in phosphorus poisoning depending on the zeolite framework structure. Cu/SSZ-13, Cu/ZSM-5, and Cu/BEA had decreasing PO3-/PO43- species with increasing P2O5, possibly due to increased pore size reducing steric hindrance for larger P2O5 species. P2O5 enhanced Cu ion redox ability, increasing low-temperature activity, while Cu ions were significantly poisoned by PO3-/PO43-, resulting in low-temperature deactivation. Phosphorus poisoning had a greater effect on the structure of Cu/ZSM-5, possibly due to attack on surface defects causing local expansion and cracking.