Artículos SCI

Liquid fuels produced via Fischer-Tropsch synthesis from biomass-derived syngas constitute an attractive and sustainable energy vector for the transportation sector. This study focuses on the role of potassium as a promoter in Ni-based catalysts for reducing coke deposition during catalytic dry reforming. The study provides a new structural link between catalytic performance and physicochemical properties. We identify new Ni-O-K chemical states associated with high stability in the reforming process, evidenced by different characterization techniques. The nickel particles form a core surrounded by a Ni-O-K phase layer (Ni@Ni-O-K) during the reduction of the catalyst. This phase likely presents an alkali-nickelate-type structure, in which nickel is stabilized in oxidation state + 3. The Ni-O-K formation induces essential changes in the electronic, physical, structural, and morphological properties of the catalysts, notably enhancing their long-term stability in dry reforming. This work thus provides new directions for designing more efficient catalysts for sustainable gas-to-liquids processes.

Advanced catalytic materials able to catalyse more than one reaction efficiently are needed within the CO2 utilisation schemes to benefit from end-products flexibility. In this study, the combination of Ni and Ru (15 and 1 wt%, respectively) was tested in three reactions, i.e. dry reforming of methane (DRM), reverse water-gas shift (RWGS) and CO2 methanation. A stability experiment with one cycle of CO2 methanation-RWGS-DRM was carried out. Outstanding stability was revealed for the CO2 hydrogenation reactions and as regards the DRM, coke formation started after 10 h on stream. Overall, this research showcases that a multicomponent Ni-Ru/CeO2 -Al2O3 catalyst is an unprecedent versatile system for gas phase CO2 recycling. Beyond its excellent performance, our switchable catalyst allows a fine control of end-products selectivity.