Dry reforming of methane over nickel aluminate-derived catalysts modified with lanthanum and magnesium

This study focuses on a novel catalytic system for the dry reforming of methane (DRM) under challenging conditions. Nickel catalysts modified with trace amounts of lanthanum or magnesium (with a nominal promoter/Ni molar ratio of 0.06) using nickel aluminate as precursor were highly efficient when operating at low temperatures (650 ºC) and high space velocities (90,000 h -1 ; 720 L min -1 g -1 , 2,200 L g Ni -1 h -1 ). The calcined precursors and the corresponding freshly reduced and used catalysts were characterized by XRF, N 2 physisorption, XRD, Raman spectroscopy, STEM/HAADF, STEM/EDS, XPS, H 2 -TPR, CO 2 -TPD, thermogravimetry and TEM. The La-promoted catalyst exhibited the best results owing to a proper combination of metallic surface area, increased basic sites for effective CO 2 adsorption and controlled formation of carbonaceous deposits. However, the performance of the Mg-promoted counterpart was negatively affected by the strong interaction between Ni and Mg, which decreased the availability of active metallic sites. This resulted in lower reactant conversions, though the catalyst remained reasonably stable over 24 hours. The presence of both promoters was effective in preventing sintering, a disadvantage of the bare nickel catalyst. • Spinel-derived Ni catalysts promoted with La and Mg were prepared • Better performance was found for the La-catalyst in the dry reforming of methane • The formation of Ni-Mg mixed oxides hindered the proper dispersion of Ni • La addition suitably optimized Ni surface area and basic properties. • No sintering and limited coking were observed under demanding reaction conditions