Nickel based catalysts for methane dry reforming: Effect of supports on catalytic activity and stability

Methane dry reforming (MDR) is a promising process for syngas production through the valorisation of two of the main Greenhouse gases. Despite the high endothermicity, it should be carried out at low temperature to directly use the syngas for Fischer-Tropsch reaction and oxygenated chemical production. The catalyst plays a key role in this process as it must encourage syngas formation by limiting coke deactivation. This work focusses the attention on the effect of different supports in the activity and stability of nickel-based catalysts. In particular, MDR has been studied at relatively low temperature, 500 °C, to deeply investigate how the support influences the reaction pathway. Ceria, zirconia, alumina, silica and titania were considered and the morphological and structural features of the materials were analysed via N2-physisorption, AAS, TPR, XRD, CO2-TPD, and SEM techniques. Moreover, by analysing the spent catalysts, it was possible to identify the causes of catalysts deactivation. Titania based catalyst is not active for MDR, while silica and zirconia present moderated activity due to the poor support stability. Most promising results are obtained with ceria and alumina-based catalysts; for these materials, 70-h reaction was carried out and alumina catalyst has proved to be the most stable towards MDR at low reaction temperature with a stable H2 yield of 25%.