Selective CO methanation over NiO-Al2O3-ZrO2 and Co3O4-Al2O3-ZrO2 catalysts

NiO-Al2O3-ZrO2 and Co3O4-Al2O3-ZrO2 catalysts were prepared by three different co-precipitation methods, namely co-precipitation, surfactant-assisted co-precipitation, and surfactant-assisted co-precipitation with ultrasound mixing methods, and their activities were tested in selective CO methanation. Catalysts were characterized using N-2 physisorption, XRD, SEM, TEM, XPS, and TPR-H-2 techniques. CO methanation and selective CO methanation reactions were carried out. Catalysts prepared by surfactant assisted co-precipitation gave high surface area, uniform pore size distributions, and small pores. The NiO-Al2O3-ZrO2 catalyst prepared by surfactant-assisted co-precipitation gave 50% CO conversion to CH4 at 155 degrees C and all CO converted to CH4 when T > 225 degrees C. For the selective CO methanation, the CO level decreased below 100 ppm at 200 degrees C over the NiO-Al2O3-ZrO2 catalyst prepared by surfactant-assisted co-precipitation.