Cu-EAB zeolite catalyst: A promising candidate with excellent SO poisoning resistance for NH-SCR reaction.

In this work, we synthesized Cu-EAB catalysts with an EAB topology for the NH-SCR of NO and evaluated their resistance to SO poisoning for the first time. The Cu-EAB catalyst showed superior NO conversion and selectivity for N, along with a notable tolerance to high space velocities and SO, outperforming the commercial Cu-CHA catalyst. This enhanced resistance was attributed to the Cu species formation at the 2.53 wt% loading, which were mainly located in the double 6-rings and 8-rings of the Cu-EAB structure. The catalyst performance was stable even after SO exposure and multiple NH-SCR cycles. Sulfation treatments at both 200 °C and 400 °C reduced the NO conversion rates of the Cu-EAB and Cu-CHA catalysts. Comparative characterizations before and after sulfation revealed that the NH-SCR activity of Cu-EAB was less affected by the sulfation treatment at 400 °C. The coverage of active sites by HSO and CuSO was identified as the primary cause of activity reduction for both catalysts after sulfation at 200 °C and 400 °C. A hybrid Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanism for the NH-SCR reaction over Cu-EAB was proposed, based on in situ DRIFTS analysis. The results show that the Cu-EAB catalyst is a promising alternative for NH-SCR applications, offering improved SO resistance and NO elimination capabilities.