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

[Display omitted] •Ni/CeO2 is successfully prepared by plasma decomposition of nickel precursor.•The obtained Ni/CeO2 catalyst shows a significantly high activity at low temperatures.•A up to 99.5 % methane selectivity was achieved.•In-situ XAS, XRD, and XPS characterizations were conducted.•Small Ni size, strong Ni-CeO2 interaction and rich interfacial sites causes high activity. 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 °C. For example, the CH4 formation rate at 275 °C is 100.3 μmol 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 H2. Therefore, the plasma prepared Ni/CeO2 catalyst shows balanced active sites for H2 splitting and CO2 activation, improving low temperature catalytic activity significantly.