Ni-based catalysts to produce synthesis gas by combined reforming of clean biogas

Ni-based catalysts promoted by Rh were prepared from hydrotalcite-type (Ht) precursors and employed in Dry Reforming (DR) and combined Steam/Dry Reforming (S/DR) of clean biogas (CB, an equimolar mixture of CH4 and CO2) to produce syngas suitable for Fischer-Tropsch or methanol synthesis. The structure of the catalysts before and after reaction were thoroughly characterized by XRD, H2-TPR, CO2-TPD, Raman, TG and TEM techniques. The DR results showed that the addition of a small amount of Rh increased the CO2 conversion and significantly decreased the carbon formation. The addition of steam to the feed to perform the combined S/DR reaction promoted the catalyst activity further by improving its resistance to carbon deposition and therefore of minimising deactivation. XRD and TPR analyses showed that an increase of the amount of Mg in the catalytic formulation, improve the active phase stability through the formation of MgO-NiO solid solution by calcination.