The Impact of Ce-Zr Addition on Nickel Dispersion and Catalytic Behavior for CO₂ Methanation of Ni/AC Catalyst at Low Temperature

The CO 2 methanation was studied over 7 wt.% nickel supported on Ce 0.2 Zr 0.8 O 2 /AC to evaluate the correlation of the structural properties with catalytic performance. The catalysts were investigated in more detail by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). A sample of 7 wt.% nickel loading supported on activated carbon (AC) was also prepared for comparison. The results demonstrated that the ceria-zirconia solid solution phase could disperse and stabilize the nickel species more effectively and resulted in stronger interaction with nickel than the parent activated carbon phase. Therefore, 7% Ni/Ce 0.2 Zr 0.8 O 2 /AC catalyst exhibited higher activity for CO 2 reduction than 7% Ni//AC. It can attain 85% CO 2 conversion at 350°C and have a CH 4 selectivity of 100% at a pressure as low as 1 atm. The high activity of prepared catalysts is attributed to the good interaction between Ni and Ce 0.2 Zr 0.8 O 2 and the high CO 2 adsorption capacity of the activated carbon as well.