Efficient methanation of CO₂ relies on the development of more selective and stable heterogeneous catalysts. Herein, we present a simple and effective method to encapsulate Ni nanoparticles in zeolite silicalite‐1. In this method, the zeolite is modified by selective desilication, which creates intraparticle voids and mesopores that facilitate the formation of small and well‐dispersed nanoparticles upon impregnation and reduction. Transmission electron microscopy and X‐ray photoelectron spectroscopy analyses confirm that a significant part of the Ni nanoparticles are situated inside the zeolite rather than on the outer surface. The encapsulation results in increased metal dispersion and, consequently, high catalytic activity for CO₂ methanation. With a gas hourly space velocity of 60 000 mL g_catalyst⁻¹ h⁻¹ and H₂/CO₂=4, the zeolite‐encapsulated Ni nanoparticles result in 60 % conversion at 450 °C, which corresponds to a site‐time yield of approximately 304 mol mol_Ni⁻¹ h⁻¹. The encapsulated Ni nanoparticles show no change in activity or selectivity after 50 h of operation, although postcatalysis characterization reveals some particle migration.

中文翻译：

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沸石包裹的镍纳米颗粒上二氧化碳的甲烷化

有效的CO ₂甲烷化依赖于更具选择性和稳定性的非均相催化剂的开发。在这里，我们提出了一种简单有效的方法将Ni纳米颗粒包封在分子筛silicalite-1中。在这种方法中，通过选择性脱硅对沸石进行改性，这会产生颗粒内的空隙和中孔，这些空隙和中孔在浸渍和还原后有助于形成小的且分散良好的纳米颗粒。透射电子显微镜和X射线光电子能谱分析证实，镍纳米粒子的很大一部分位于沸石内部而不是外表面。封装导致金属分散性增加，因此对CO ₂具有高催化活性甲烷化。气体时空速度为60 000 mL g_催化剂^-1  h ^-1且H ₂ / CO ₂ = 4时，沸石包封的Ni纳米颗粒在450°C时产生60％的转化率，这相当于现场时间的产率_Ni ^-1  h ^-1约为304 mol mol 。封装的Ni纳米粒子在运行50小时后没有显示出活性或选择性的变化，尽管催化后表征显示了一些粒子迁移。