A Mesoporous Carbon‐Supported and Cs‐promoted Ru Catalyst with Enhanced Activity and Stability for Sustainable Ammonia Synthesis

A mesoporous carbon‐supported Ru catalyst with Cs promotor and an open mesostructure (Cs−Ru/MPC) was prepared by a stepwise wet impregnation method and used for sustainable ammonia synthesis under mild reaction conditions using a wide range of space velocities (SV). The Cs−Ru/MPC catalyst showed higher activity and stability for ammonia synthesis than a reference catalyst with a microporous framework prepared by the same method (an active‐carbon‐supported and Cs‐promoted Ru catalyst (Cs−Ru/AC)). It was found that the mesoporous carbon framework is a suitable medium for the dispersion of the Ru nanoparticles within a narrow size distribution, and it also protected the small Ru nanoparticles against sintering during ammonia synthesis. However, the sintering of Ru nanoparticles on the outer surfaces of the Cs−Ru/AC catalyst was observed, resulting in its deactivation. The results suggest that the Cs−Ru/MPC catalyst is applicable to real operating conditions, where there may be short warm‐up and shut‐down periods for hydrogen production via the electrolysis of water using intermittently available renewable electricity.