Combining silica to boost the ammonia synthesis activity of ceria-supported Ru catalyst

Modification of Ru/CeO2 catalysts for ammonia synthesis from H2 and N2 is of emerging interest for potential industrial application. Herein, we report an effective strategy by introduction silica to enhance ammonia synthesis performance by tuning hydrogen adsorption-desorption property. Owing to the enhancement of Ru sites surrounded by oxygen atoms, ceria-supported Ru catalyst with SiO2 adsorbs more hydrogen species, and the desorption and exchange of hydrogen species would also be accelerated. Therefore, the introduction of SiO2 into Ru/CeO2 catalyst can improve the ammonia synthesis activity by more than 34% at 400 °C, and the catalyst with SiO2 shows a lower activation energy and superior high-pressure effect for ammonia synthesis. These findings will open up a new avenue for the development of ammonia synthesis and also provide guidance for preparing highly efficient oxides-supported metal catalysts in a series of hydrogen-involving reactions.