A Highly Selective and Stable Ruthenium-Nickel Supported on Ceria Catalyst for Carbon Dioxide Methanation

The performance of nickel, ruthenium, and nickel-ruthenium impregnated on cerium oxide catalysts was tested in the methanation of carbon dioxide reaction. The nickel and ruthenium contents were 4 and 0.4 wt%, respectively. The properties of the catalysts were studied using elementary analysis, Brunauer-Emmet-Teller specific surface area measurements, X-ray diffraction, temperature programmed reduction, temperature programmed desorption, H₂ chemisorption and transmission electron microscopy. The results showed that the addition of ruthenium improves the catalytic performance by promoting the dispersion of nickel species over the surface of the cerium oxide support. The ruthenium-nickel combination produced a stable catalyst that did not show any deactivation even after 75 hours on-stream. At high feed gas total pressures (5 and 10 bar), the catalytic conversions of CO₂ were close to the thermodynamic equilibrium values with a 100 % selectivity towards CH₄ formation.