Highly Active Ce- and Mg-Promoted Ni Catalysts Supported on Cellulose-Derived Carbon for Low-Temperature CO2 Methanation

The CO2 methanation performance of Mg- and/or Ce-promoted Ni catalysts supported on cellulose-derived carbon (CDC) was investigated. The samples, prepared by biomorphic mineralization techniques, exhibit pore distributions correlated to the particle sizes, revealing a direct effect of the metal content in the textural properties of the samples. The catalytic performance, evaluated as CO2 conversion and CH4 selectivity, reveals that Ce is a better promoter than Mg, reaching higher conversion values in all of the studied temperature range (150-500 degrees C). In the interval of 350-400 degrees C, Ni-Mg-Ce/CDC attains the maximum yield to methane, 80%, reaching near 100% CH4 selectivity. Ce-promoted catalysts were highly active at low temperatures (175 degrees C), achieving 54% CO2 conversion with near 100% CH4 selectivity. Furthermore, the large potential stability of the Ni-Mg-Ce/CDC catalyst during consecutive cycles of reaction opens a promising route for the optimization of the Sabatier process using this type of catalyst.