Combustion-impregnation preparation of Ni/SiO2 catalyst with improved low-temperature activity for CO2 methanation

Exploiting Ni-based catalysts with excellent low-temperature activity is significant for CO2 methanation, which is a promising route to CO2 utilization. In this work, a facile combustion-impregnation method was developed to prepare the SiO2 supported Ni catalysts. Small Ni particles (around 6 nm) and massive Ni-SiO2 nterface could be obtained due to the combustion: process. The H-2-temperature programmed desorption (H-2-TPD) revealed the existence of Ni-SiO2 interface and confirmed the high Ni dispersion obtained by this method, which were vital for the activation of reactant. Moreover, more medium basic sites which were beneficial for the CO2 activation could also be created. In comparison with the reference Ni/SiO2 catalyst prepared by the conventional impregnation method, much higher CO2 conversion (66.9%) and more superior selectivity to CH4 (94.1%) were achieved with the Ni/SiO2-Gly catalyst at 350 degrees C. Additionally, it was also found that glucose, citric acid and glycine were all effective fuels for this combustion-impregnation method, and the as-prepared catalysts all exhibited greatly improved low-temperature activity. Therefore, this work represents an important step toward developing Ni-based catalysts for CO2 methanation by a promising wide-used method (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Developed a facile combustion-impregnation method to prepare SiO2 supported Ni catalysts with high dispersion of Ni-SiO2 interface and small Ni particles. Achieved higher CO2 conversion and CH4 selectivity with the Ni/SiO2 catalyst prepared by this method at 350 degrees C. Effective fuels for this method include glucose, citric acid and glycine, which can greatly improve the low-temperature activity of the catalysts.