Selective CO methanation over amorphous Ni-Ru-B/ZrO_2 catalyst for hydrogen-rich gas purification

摘要

Amorphous Ni-Ru-B/ZrO2 catalysts were prepared by chemical reduction method. The effects of Ni-Ru-B loading and Ru/Ni mole ratio on the catalytic performance for selective CO methanation from reformed fuel were studied, and the catalysts were characterized by BET, ICP, XRD and TPD. The results showed that Ru strongly affected the catalytic activity and selectivity by increasing the thermal stability of amorphous structure, promoting the dispersion of the catalyst particle, and intensifying the CO adsorption. For the catalysts with Ru/Ni mole ratio under 0.15, the CO methanation conversion and selectivity increased significantly with the increasing Ru/Ni mole ratio. Among all the catalysts investigated, the 30 wt% Ni-Ru-B loading amorphous Ni61Ru9B30/ZrO2 catalyst with 0.15 Ru/Ni mole ratio presented the best catalytic performance,over which higher than 99.9%of CO conversion was obtained in the temperature range of 230℃～250℃,and the CO2 conversion was kept under the level of 0.9%.