Oxygen-Induced Activation of a Ceria-Supported Ru Catalyst for Enhancing Ammonia Synthesis Activity

The development of a Ru catalyst with excellent ammonia synthesis performance plays a key role in the application of ammonia in the upcoming renewable energy era. Herein, a ceria-supported Ru catalyst was prepared by oxygen-induced activation, resulting in enhancement of the amount of the exposed Ru species, active oxygen species, and Ru–O–Ce bond. As a result, the amount of Ru species surrounded by active oxygen species would be enhanced, facilitating the exchange and reaction of the hydrogen species adsorbed on the Ru catalyst with the gaseous reactants. Oxygen-induced activation of the ceria-supported Ru catalyst leads to enhancement of the ammonia synthesis activity by more than 63%; moreover, the as-obtained catalyst has a smaller negative reaction order of H2 than its Ru/CeO2 counterpart.