A comparative study of fibrous silica-based catalysts for improving methane production via CO2 methanation

Abstract

The process of utilizing the greenhouse gas carbon dioxide (CO2) is crucial in addressing and reducing the impact of climate change. The CO2 methanation process, also known as the Sabatier reaction, is considered one of the appealing approaches since it provides synthetic natural gas (SNG), fulfilling the present needs. However, the CO2 methanation reaction demands an exceptionally effective catalyst capable of surpassing the energy barrier associated with eight proton-electron transfers from H2 molecules. Herein, the application of fibrous silica nanospheres along with the fibrous modification of mesostructured silica nanoparticles (MSN) towards CO2 methanation, called the Centre of Hydrogen energy silica (CHE-Si) and CHE-SM was reported. Both catalysts were successfully synthesized by utilizing micro-emulsion techniques and subsequently were characterized with x-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, and N2 adsorption-desorption. FTIR results revealed that CHE-SM possessed superior Si-OH and Si-O species than CHE-Si despite displaying low surface area and pore volume. Consequently, CHE-SM achieved above 50% CO2 conversion and CH4 yield at 500 °C while CHE-Si exhibited lower performance. This discrepancy in catalytic performance was due to the fact that CHE-SM was comprised of more active sites that could adsorb and dissociate CO2 and H2 reactants.