Effect of La2O3 promoter on NiO/Al2O3 catalyst in CO methanation

A series of NiO/Al2O3 catalysts promoted by different La2O3 contents were prepared by impregnation method. The physicochemical properties of NiO-La2O3/Al2O3 were characterized by N-2 adsorption-desorption, X-ray diffraction (XRD), H-2 temperature programmed reduction (H-2-TPR) and H-2 chemisorption. The effect of La2O3 on the activity of NiO/Al2O3 for CO methanation was investigated in a fixed bed reactor. A lifetime test, as well as thermogravimetric (TG) analysis, was performed to investigate the stability performance and anti-carbon deposition of catalysts. The results showed that the addition of La2O3 can restrain the growth of NiO particles, increase the H-2 uptake and Ni dispersion, and therefore enhance the activity of catalysts. When the La2O3 content was 3 wt%, a CO conversion of 98% and a selectivity to CH4 of 96% were obtained at 400 A degrees C. Furthermore, the catalyst NiO-La2O3/Al2O3 with 3 wt% La2O3 content displayed highly stable performance in long-term tests, especially exhibiting good anti-carbon deposition property.