With demand for gasoline and diesel expected to decline in the near future, crude-tochemicals technologies have the potential to become the most important processes in the petrochemical industry. This trend has triggered intense research into the optimization of current refining processes to maximize the production of light olefins and aromatics at the expense of fuels. Although attractive, this approach has shown certain limitations and calls for disruptive processes able to directly transform crude to chemicals in a more efficient and environmentally friendly way. Here we propose a new reactor concept consisting of a multi-zone fluidized bed (MZFB) along with a new catalyst formulation able to perform several refining steps in one single reactor vessel. The MZFB configuration allows for in situ catalyst stripping and regeneration, while the incorporation of silicon carbide during catalyst shaping via spray drying confers this new catalyst formulation with improved physical, mechanical and heat transport properties. As a result, we demonstrate that, using this reactor-catalyst combination, it is possible to achieve stable direct

NiO and metal-promoted NiO catalysts (M-NiO, with a M/(M+Ni) atomic ratio of 0.08, with M = Nb, Sn, or La) have been prepared, tested in the oxidative dehydrogenation (ODH) of ethane, and characterized by means of XRD, TPR, HRTEM, Raman, XPS, and in situ XAS (using H2/He, air or C2H6/He mixtures). The selectivity to ethylene during the ODH of ethane decreases according to the following trend: Nb–NiO ≈ Sn–NiO > La–NiO > NiO, whereas the catalyst reducibility (determined by both TPR and XAS using H2/He mixtures) shows the opposite trend. However, different reducibility and catalytic behavior in the absence of oxygen (ethane/He mixtures) have been observed, especially when comparing Nb- and Sn-promoted NiO samples. These differences can be ascribed mainly to a different phase distribution of the promoter. The results presented here are discussed in terms of the nature of active and selective sites for ODH of ethane in selective and unselective catalysts, but also the role of promoters and the importance of their phase distribution.

The conversion of CO2 to light olefins via bifunctional catalysts (i.e. metal oxides/zeolites) is a promising approach to tackle CO2 emissions and, at the same time, reduce fossil-fuel dependence by closing the carbon cycle.

Two cobalt catalysts, Co/SBA-15 and Co/SiO2, have been studied in steam reforming of ethanol (SRE). Besides the steam reforming products, ethoxide dehydrogenation to acetaldehyde is observed as one of the main reactions. Although by hydrogen treatment cobalt is reduced to the metallic state, under SRE conditions, a phase appears that has been identified as cobalt carbide and correlates with acetaldehyde production. These findings provide insights about the catalytic sites, for SRE, in cobalt catalysts. Comparison with previous results shows that these conclusions are not translatable to other cobalt catalysts, stressing the importance of the support on the catalytic behavior of cobalt.