One-Step Synthesis of Cesium Decorated Ru Nanoparticles on MgO as Efficient Catalyst for Ammonia Synthesis

Alkali promoted Ru/MgO catalysts have been explored as promising catalyst for ammonia synthesis. However, application of alkali promoted Ru/MgO catalysts is severely restricted by the complex synthetic procedure. Herein, a one-step solid state method was developed for synthesis of cesium decorated Ru/MgO (Cs‒Ru/MgO) materials. The Cs‒Ru/MgO catalysts exhibit over 1 order of magnitude higher activity than that of the undecorated Ru/MgO analogue in ammonia synthesis, even outperforming previous reported Cs promoted Ru/MgO. Moreover, highly stable performance was observed over the Cs–Ru/MgO catalyst in ammonia synthesis. Characterization results show that the Cs species can not only induce formation of highly dispersed Ru nanoparticles (NPs) but also modulate the electronic structure of Ru NPs. Cs species decorated Ru NPs can facilitate dissociation of nitrogen and greatly improve intrinsic activity of Cs–Ru/MgO catalysts. This study offers a new and facile route to fabricate efficient alkali metal promoted Ru-based catalysts for ammonia synthesis. Graphical Abstract