High-performance IM-5 was prepared by tetrapropylammonium hydroxide (TPAOH) and NaOH alkaline treatment. The modification of combined alkaline treatment on the pore and acidity were systematically characterized. The ²⁹Si NMR results indicated that Si(4Si, 0Al) sites were protected by tetrapropylammonium cation (TPA⁺) at low TPAOH/(NaOH + TPAOH) molar ratio, while the protection effect extended to some Si(3Si, 1Al) sites at TPAOH/(NaOH + TPAOH) ratio of 75%. And, the amount of strong Brønsted acid sites decreased significantly from 255 μmolg⁻¹ to 119 μmolg⁻¹ under the optimal TPAOH/NaOH alkaline treatment conditions. Compared to NaOH treatment alone, the mesopore volume and external surface area of IM-5 were further increased with TPAOH introduced, meanwhile, the mesopore size was shrunken into the range of 2–10 nm centered at 5 nm. Compared to NaOH treated IM-5 catalyst, the TPAOH/NaOH treated one exhibited higher initial light olefins yield (53.4% vs. 45.2% for n-heptane cracking) and better catalytic stability and regeneration properties. The abundant narrow mesopores contributed into high tolerance ability to coke deposition in IM-5 catalysts, as confirmed by TGA results.

高性能 IM-5 由​​四丙基氢氧化铵 (TPAOH) 和 NaOH 碱处理制备。系统地表征了联合碱处理对孔隙和酸度的改变。的^29个的Si NMR结果表明，硅（4SI，0AL）位点由四丙基阳离子（TPA保护⁺）在低TPAOH /氢氧化钠（NaOH + TPAOH）的摩尔比，而保护效果扩展到在一些硅（3SI，1AL）位点TPAOH/(NaOH + TPAOH) 比率为 75%。并且，强布朗斯台德酸位点的数量从 255 μmolg ^-1显着减少到 119 μmolg ^-1在最佳 TPAOH/NaOH 碱处理条件下。与单独的 NaOH 处理相比，随着 TPAOH 的引入，IM-5 的中孔体积和外表面积进一步增加，同时中孔尺寸缩小到 2-10 nm，以 5 nm 为中心。与 NaOH 处理的 IM-5 催化剂相比，TPAOH/NaOH 处理的催化剂表现出更高的初始轻烯烃产率（53.4% 对正庚烷裂化的45.2% ）和更好的催化稳定性和再生性能。TGA 结果证实，丰富的窄介孔有助于 IM-5 催化剂对积炭沉积的高耐受能力。