Preparation of high surface area Ni/MgAl_2O_4 nanocatalysts for CO selective methanation

摘要

Methanation of carbon monoxide in the H-2-rich gas stream was performed on a series of the Ni/MgAl2O4 catalysts in a fixed bed micro-reactor. The catalysts were synthesized using wetness impregnation method and the prepared samples were characterized by XRD, BET, SEM, TEM, H-2-TPR, CO chemisorption and CO-TPD techniques. The catalyst carrier was prepared by a novel sol-gel method using nitrate salts precursors and propylene oxide as a gelation agent. MgA1204 as catalyst carrier possessed a high BET area of 340 m(2) g(-1) with high pore volume (0.563 cc g(-1) and small pore size (6.56 nm). The catalysts also showed high BET area, which decreased with the increase in Ni content. These catalysts exhibited mesoporous structure with average nickel crystal size smaller than 20 nm. The catalyst with Ni content of 25 wt% exhibited the maximum CO conversion and CH4 selectivity and can be considered as a catalyst with high catalytic potential for the selective methanation of carbon monoxide. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.