Effect of K⁺ on the performance of Ni/Al₂O₃ high temperature methanation catalyst

The effects of potassium ions on the properties of co-precipitation Ni/Al₂O₃ high temperature methanation catalysts were investigated. The catalysts were characterized by low temperature nitrogen adsorption (BET), X-ray diffraction (XRD), and hydrogen programmed reduction (H₂-TPR). Activity tests showed that the activity of the catalyst decreased with increasing of potassium ions, but the anti-carbon capacity of the catalyst increased first and then decreased. The activity deactibation is due to the decrease of specific surface aera measured by BET. On this basis, the effect of kaliophilite on the performance of Ni/Al₂O₃ methanation catalyst was investigated. The results showed that the addition of kaliophilite had little effect on the specific surface area and activity of the catalyst, but could significantly improve the anti-carbon capacity of the catalyst. (paper)