Highly active Ni/CeO2 catalyst for CO2 methanation: Preparation and characterization

A Ni/CeO2 catalyst was prepared via decomposition of nickel precursor by gas discharge plasma, followed by hydrogen reduction thermally. The activity of the obtained catalyst reaches the highest level towards CO2 methanation with methane selectivity above 99 % at reaction temperatures lower than 300 degrees C. For example, the CH4 formation rate at 275 degrees C is 100.3 mu mol gcat(-1) s(-1), higher than the reported catalysts at the same reaction temperature. Characterization results indicate that the plasma decomposition leads to an interfacial structure where Ni atoms bind with O atoms from ceria. A strong metal-support interaction is caused. Rich interfacial Ni-CeO2 sites are thus formed with excellent redox property. The unique interfacial structure confines small nickel particles on the ceria surface, exposing more metallic Ni as active sites for splitting H-2. Therefore, the plasma prepared Ni/CeO2 catalyst shows balanced active sites for H-2 splitting and CO2 activation, improving low temperature catalytic activity significantly.

Automated summary

The Ni/CeO2 catalyst prepared via gas discharge plasma and hydrogen reduction shows high activity in CO2 methanation at low temperatures, with excellent CH4 formation rate and redox property. The unique interfacial structure and metal-support interaction lead to the formation of rich interfacial Ni-CeO2 sites, improving the catalyst's performance significantly in H-2 splitting and CO2 activation.