Effect of ZrO2 on catalyst structure and catalytic methanation performance over Ni-based catalyst in slurry-bed reactor

A series of ZrO2-promoted Ni-based catalysts were prepared by different methods to study the effect of ZrO2 addition manners on catalytic methanation of CO in a slurry-bed reactor. These catalysts were characterized by N-2 adsorption desorption, XRD, H-2-TPR, H-2-chemisorption, XPS, TEM, and CHNS. The results show that the ZrO2-promoted catalyst prepared by impregnation precipitation method exhibits higher Ni dispersion, metal surface area and catalytic performance than catalysts prepared by the coprecipitation and impregnation method. With the increase of ZrO2 molar percentage in ZrO2 Al2O3 support, the catalysts shows that the Ni dispersion and metal surface area first increases and then decreases. Catalyst with 20% ZrO2 exhibits the highest CO conversion and CH4 yield under the reaction conditions of 280 degrees C, 1.0 MPa, H-2/CO = 3.0 and 3000 mL g(-1) h(-1) gas hourly space velocity. Moreover, 20% ZrO2 on catalyst surface performs superior catalytic stability, and prevents the carbon deposition and Ni aggregation. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.