Selective CO methanation over CeO2–ZrO2 -composed NiO and Co3O4 catalysts

CeO2–ZrO2-composed NiO and Co3O4 catalysts were prepared by 3 different methods. Both CO methanation and selective CO methanation were carried out. All catalysts were prepared by (1) co-precipitation, (2) surfactantassisted co-precipitation, and (3) surfactant-assisted co-precipitation with ultrasound mixing methods. Catalysts were characterized by using N2 physisorption, XRD, SEM, TEM, and TPR-H2 techniques. The highest surface area value, uniform pore size distribution, and pores having small diameters were observed for the catalysts prepared by using the surfactant and ultrasound.