Hydrothermally modified nanosheet ZSM-5 zeolite by directly using MnO_x nanoparticles was carried out and this substantially offered a high performance catalyst for methanol to propylene (MTP) reaction. The properties of as synthesized ZSM-5 nanosheets with different MnO_x amounts (NS-x) were compared with ZSM-5 nanosheets modified by impregnation method (IM-0.5) and physically mixed method (PM-0.5), respectively. The initial state of MnO_x nanoparticles was close to Mn₂O₃ with 20 nm in size. XRD, H₂-TPR and XAFS results confirmed under high temperature hydrothermal condition, the Mn₂O₃ nanoparticles disaggregated into Mn₂O₃ clusters and entered the framework defects of nanosheet zeolite with high dispersion. Infrared spectra of hydroxyl groups (OH-IR) showed that the Mn₂O₃ clusters were bonded with silanol defects both on the surface and inside zeolite, which substantially increased the stability of Mn₂O₃ clusters and healed the framework defects. In contrast, the Mn species in the impregnated sample was close to the co-existence of Mn²⁺ ions and MnO₂ nanoparticles with 2–3 nm, no interaction between Mn species and Si–OH group was determined. Notably, the typical sample (NS-0.5) with MnO_x cluster modification performed much higher propylene selectivity and catalytic stability (~52%, 240 h, WHSV = 3 h⁻¹), while the conventional IM-0.5 and PM-0.5 showed poor propylene selectivity (48%, 46%) and catalytic stability (166 h, 133 h) in MTP reaction. The excellent result should be attributed to the subtle control of external strong acid and the less structural defects, due to specific existence of bonded Mn₂O₃ clusters.

直接使用MnO _x纳米颗粒进行水热改性纳米片ZSM-5沸石，这为甲醇制丙烯（MTP）反应提供了高性能催化剂。分别将具有不同MnO _x量（NS-x）的合成ZSM-5纳米片与通过浸渍法（IM-0.5）和物理混合法（PM-0.5）改性的ZSM-5纳米片的性能进行比较。MnO _x纳米粒子的初始状态接近于大小为20nm的Mn ₂ O ₃。XRD、H ₂ -TPR 和 XAFS 结果证实在高温水热条件下，Mn ₂ O ₃纳米颗粒解聚成 Mn₂ O ₃团簇并进入高分散纳米片沸石的骨架缺陷。羟基的红外光谱(OH-IR)表明Mn ₂ O ₃团簇与沸石表面和内部的硅烷醇缺陷结合，大大提高了Mn ₂ O ₃团簇的稳定性并修复了骨架缺陷。相比之下，浸渍样品中的 Mn 物质接近于 Mn ²⁺离子和 MnO ₂纳米粒子的共存，范围为 2-3 nm，未确定 Mn 物质和 Si-OH 基团之间的相互作用。值得注意的是，具有 MnO _x的典型样品 (NS-0.5)簇改性表现出更高的丙烯选择性和催化稳定性 (~52%, 240 h, WHSV = 3 h ^-1 )，而传统的 IM-0.5 和 PM-0.5 表现出较差的丙烯选择性 (48%, 46%) 和催化稳定性(166 h, 133 h) 在 MTP 反应中。优异的结果应归功于外部强酸的微妙控制和较少的结构缺陷，由于键合的 Mn ₂ O ₃团簇的特定存在。