Synergistic effect of Ni and NiO in hydrogen reduction for CO methanation

Abstract

The synthesis of methane from syngas represents a pivotal technology in the artificial synthesis of natural gas, with the study of methanation catalysts being a fundamental aspect of this process. Extensive research has focused on CO methanation using Ni/Al2O3 catalysts; however, enhancements in catalyst stability and low-temperature activity are still required. This research investigated the structure of Ni/Al2O3 under H2 reduction at varying temperatures and the catalytic performance in natural gas synthesis (SNG) through CO methanation. It was observed that a higher reduction temperature resulted in nickel species agglomeration. Notably, Ni catalysts reduced at 600 °C demonstrated optimal CO conversion and CH4 selectivity under the tested conditions. Characterization studies uncovered a synergistic effect between Ni and NiO species, which was most effective for catalytic activity under hydrogen reduction at 600 °C but only at an appropriate reduction temperature. These insights are significant for the advancement of Ni/Al2O3 methanation catalysts in natural gas production.