A series of modified HUSY zeolites were prepared by immersing with different concentration of NH4F solution at low temperature, and their catalytic performance for isobutane/1-butene alkylation reaction was investigated. The physicochemical properties of modified catalysts were characterized by XRD, N2 adsorption–desorption isotherms, ICP, pyridine-IR and SEM. The results indicated that HUSY zeolite with higher Si/Al ratio is more sensitive to NH4F leaching, resulting in more severe structural amorphization. NH4F modification affects not only the pore structure but also the acid properties. The amount of Lewis acid sites on the modified zeolites was reduced and the ratio of Brønsted/Lewis acid sites was significantly enhanced in comparison with that of parent zeolite. Such properties of modified zeolites account for the superior performance for isobutane/1-butene alkylation. The initial C8 selectivity was increased to 74 wt% over the modified HUSY (Si/Al = 2.7) zeolite using 5 wt% NH4F solution, which was about 15 wt% higher than that achieved on the HUSY parent. TG and in situ IR analyses of the deactivated catalyst indicated that some deposits were formed on the catalyst and the alkylation activity could be restored by regeneration at suitable conditions (520 °C under air atmosphere).

中文翻译：

---

氟化铵改性HUSY沸石的异丁烷/1-丁烯烷基化性能

用不同浓度的NH4F溶液在低温下浸渍制备了一系列改性HUSY沸石，并研究了它们对异丁烷/1-丁烯烷基化反应的催化性能。改性催化剂的理化性质通过XRD、N2吸附-解吸等温线、ICP、吡啶-IR和SEM进行表征。结果表明，具有较高Si/Al比的HUSY沸石对NH4F浸出更敏感，导致更严重的结构非晶化。NH4F 改性不仅会影响孔结构，还会影响酸性。与母体沸石相比，改性沸石上路易斯酸位的数量减少，布朗斯特/路易斯酸位比显着提高。改性沸石的这些特性解释了异丁烷/1-丁烯烷基化的优越性能。与使用 5 wt% NH4F 溶液的改性 HUSY (Si/Al = 2.7) 沸石相比，初始 C8 选择性提高到 74 wt%，比在 HUSY 母体上实现的选择性高约 15 wt%。失活催化剂的 TG 和原位 IR 分析表明，催化剂上形成了一些沉积物，烷基化活性可以通过在合适的条件下（空气气氛下 520 ℃）再生来恢复。