The CO2 methanation performance was evaluated in a continuous flow fixed-bed reactor. A total of 100 mg of catalyst was in-situ reduced in the reactor at 200 °C for 1 h under 30 mL/min of H2 and purged at the same temperature for 1 h under 10 mL/min of Ar. A reaction mixture of 10% CO2 and 40% H2 diluted in Ar (total flow rate of 20 mL/min) was then introduced into the reactor. The reaction was performed at atmospheric pressure in the step mode from 200 °C to 300 °C with 25 °C intervals, and at least four gas chromatography injections were done for each temperature after reaching a steady state. The outlet gases were quantified by a gas chromatograph (SCION 456-GC) equipped with Hayesep Q, Molsieve 5A, Porapak R and SCION-1 columns. The separated CO and CO2 were analyzed by a thermal conductivity detector, while CH4 was detected with a flame ionization detector. During the reaction, all gas transfer lines were maintained at 110 °C so that the condensation of water by-product was prevented. CO2 conversion (X CO 2 ), CH4 selectivity (S CH 4 ), Ru-mass-normalized CO2 conversion rate (r CO 2 ) and turnover frequency (TOF) were calculated according to the following equations: