Isolated cationic Pd species encapsulated in MFI zeolite, i.e., Pd@MFI, have been successfully prepared via in situ hydrothermal route followed by oxidative treatment. The as-prepared Pd@MFI samples are investigated as promising catalysts in the reaction of methane combustion. Typically, Pd@H-ZSM-5 shows remarkable activity in methane catalytic combustion with a low apparent activation energy value of 70.7 kJ/mol as well as good catalytic stability even in excess water vapor. Detailed characterization results demonstrate the strong interaction between Pd sites and zeolite framework in Pd@ZSM-5 and the efficient stabilization of isolated Pd sites by zeolite thereof. Spectroscopy analyses reveal that the presence of Brønsted acid sites is beneficial to methane adsorption and its subsequent activation on adjacent Pd sites, constructing cooperation between Brønsted acid sites and Pd sites within the confined space of MFI zeolite toward high-efficiency methane catalytic combustion. The reaction mechanism of methane combustion catalyzed by Pd@H-ZSM-5 model catalyst is finally discussed.

已通过原位成功制备了封装在 MFI 沸石中的分离的阳离子 Pd 物种，即Pd@MFI水热途径，然后是氧化处理。所制备的 Pd@MFI 样品被研究为甲烷燃烧反应中的有前途的催化剂。通常，Pd@H-ZSM-5在甲烷催化燃烧中表现出显着的活性，表观活化能值低至70.7 kJ/mol，即使在过量水蒸气中也具有良好的催化稳定性。详细的表征结果证明了 Pd@ZSM-5 中 Pd 位点与沸石骨架之间的强相互作用以及其沸石对孤立 Pd 位点的有效稳定。光谱分析表明，布朗斯台德酸位点的存在有利于甲烷吸附及其在相邻 Pd 位点上的后续活化，在 MFI 沸石的密闭空间内构建 Brønsted 酸位点和 Pd 位点之间的合作，以实现高效的甲烷催化燃烧。最后讨论了Pd@H-ZSM-5模型催化剂催化甲烷燃烧的反应机理。