To stabilize Ru nanoparticles against sintering is an urgent problem in the utilization of Ru-based catalysts for NH₃ synthesis. In the present study, we used Ru-containing ZSM-5 as seeds to crystallize ZSM-5, and the resulted Ru@ZSM-5 catalyst is highly resistant against Ru sintering. According to the results of diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) and transmission electron microscopy (TEM) analyses, the average size of Ru nanoparticles is around 3.6 nm, which is smaller than that of Ru/ZSM-5-IWI prepared by incipient wetness impregnation. In NH₃ synthesis (N₂:H₂ = 1:3) at 400 °C and 1 MPa, Ru@ZSM-5 displays a formation rate of 5.84 mmol_NH3 g_cat⁻¹ h⁻¹, which is much higher than that of Ru/ZSM-5-IWI (2.13 mmol_NH3 g_cat⁻¹ h⁻¹). According to the results of TEM, N₂-temperature-programmed desorption (N₂-TPD), X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) studies, it is deduced that the superior performance of Ru@ZSM-5 is attributable to the small particle size and the ample existence of metallic Ru⁰ sites. This method of zeolite encapsulation is a feasible way to stabilize Ru nanoparticles for NH₃ synthesis.

稳定Ru纳米颗粒以防止烧结是利用Ru基催化剂用于NH ₃合成中的一个紧迫问题。在本研究中，我们使用含 Ru 的 ZSM-5 作为晶种来结晶 ZSM-5，所得 Ru@ZSM-5 催化剂对 Ru 烧结具有高度抵抗力。根据漫反射红外傅立叶变换光谱 (DRIFTS) 和透射电子显微镜 (TEM) 分析的结果，Ru 纳米粒子的平均尺寸约为 3.6 nm，小于早期制备的 Ru/ZSM-5-IWI。湿浸渍。在 400 °C 和 1 MPa 下的 NH ₃合成（N ₂ :H _{2 = 1:3）中，Ru@ZSM-5 显示出 5.84 mmol NH 3} g _cat的形成速率^-1 h ^-1，远高于Ru/ZSM-5-IWI（2.13 mmol _{NH 3} g _cat ^-1 h ^-1）。根据TEM、N ₂ -程序升温脱附(N ₂ -TPD)、X射线光电子能谱(XPS)和X射线吸收精细结构(XAFS)研究的结果，推断Ru的优越性能@ZSM-5 归因于小粒径和大量存在的金属 Ru ⁰位点。这种沸石包封方法是稳定用于 NH ₃合成的 Ru 纳米粒子的可行方法。