Selective CO methanation over CeO 2 ZrO 2 -composed NiO and Co 3 O 4 catalysts

Abstract

CeO 2 ZrO 2 -composed NiO and Co 3 O 4 catalysts were prepared by 3 different methods. Both CO methana- tion and selective CO methanation were carried out. All catalysts were prepared by (1) co-precipitation, (2) surfactant- assisted co-precipitation, and (3) surfactant-assisted co-precipitation with ultrasound mixing methods. Catalysts were characterized by using N 2 physisorption, XRD, SEM, TEM, and TPR-H 2 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. The NiO/CeO 2 /ZrO 2 prepared by the surfactant-assisted co-precipitation was the most ◦ active catalyst for CO methanation. It gave 50% CO conversion to CH 4 at 150C and all CO was converted to CH 4 ◦◦ after T > 225C. Moreover, 22.3% CH 4 was formed and the CO level decreased below 100 ppm at 200C during the selective CO methanation activity test over this catalyst.