Enhancing the catalytic performance of Co substituted NiAl_2O_4 spinel by ultrasonic spray pyrolysis method for steam and dry reforming of methane

摘要

(Ni,Co)Al2O4 mesoporous spinel particles with a high specific surface area were synthesized in a single-step by ultrasonic spray pyrolysis at 1000 degrees C. After reduction, a uniform metal distribution was obtained on the support, which was used as a catalyst for dry and steam reforming of methane. Substituting Ni with Co resulted in a substantial increase in the specific surface area from 118 m(2)/g to 182 m(2)/g as a result of different decomposition paths that occurs for Ni and Co salts in the pyrolysis reactions. Results show that partial substitution of Ni with Co, between 20 and 50%, significantly increased the methane conversion values and improved the stability of the catalysts in the time on stream experiments. It also shows that partial substitution substantially improved the catalyst resistance against carbon deposition in the dry reforming process. The complete replacement of the cobalt with nickel in spinel structure caused a significant drop in catalytic properties. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.