Synthesis and Catalytic Performance of a Dual-Sites Fe–Zn Catalyst Based on Ordered Mesoporous Al2O3 for Isobutane Dehydrogenation

Fe-MOF Materials as Precursors for the Catalytic Dehydrogenation of Isobutane

“…In this spirit, high-severity fluid catalytic cracking (FCC) processes that maximize short olefin productivity along with other on-purpose processes have been developed. − One outstanding example of the latter is the production of butylenes, where nonoxidative dehydrogenation of isobutane is currently used to cover the demand for isobutylene, which is employed as a precursor of high-octane oxygenates (MTBE and ETBE) and in the production of butyl rubber . As for the oxidative route with di-oxygen, despite favorable from a thermodynamic and kinetic point of view, has disadvantages such as the low selectivities obtained so far or the high exothermicity and risk of formation of explosive atmospheres. , Commercial catalysts, based on platinum or chromium, usually promoted with tin and alkali metals, respectively, have shown the best catalytic performance. , However, the high cost of platinum and the toxicity of chromium (Cr 6+ species) have encouraged the search for alternatives such as vanadium − and, to a lesser extent, molybdenum, , zirconium, , gallium, , indium, and iron oxides, − which have all shown some promise as potential active phases. Among them, Fe is especially interesting because of its natural abundance, low cost, and low toxicity.…”

“…Lobo et al claimed that isolated Fe 3+ species on an Fe-ZSM-5 catalyst are the preferred site for adsorption of propane, which is then dehydrogenated following a redox cycle involving Fe 3+ /Fe 2+ species. Similarly, octahedral Fe 2+ sites in an ordered mesoporous Al 2 O 3 promoted with a ZnO matrix have been shown to be highly active in the dehydrogenation of isobutane, presenting conversions of isobutane of above 40% at 580 °C and a moderate selectivity to isobutylene in the 70–85% range . In a fundamental study, Hu et al.…”

“…Similarly, octahedral Fe 2+ sites in an ordered mesoporous Al 2 O 3 promoted with a ZnO matrix have been shown to be highly active in the dehydrogenation of isobutane, presenting conversions of isobutane of above 40% at 580 °C and a moderate selectivity to isobutylene in the 70−85% range. 21 In a fundamental study, Hu et al reported that isolated species are the most active and selective for the dehydrogenation of propane at 650 °C at low conversions, while iron oxide clusters are poorly active for the reaction. On the other hand, metallic iron presents an order of magnitude higher activity in the conversion of propane but with a very low selectivity to propylene.…”

Synthesis, spectroscopic and catalytic properties of FeO x /Al 2 O 3 nanopowders prepared by cw CO 2 laser vaporization

“…It is known that heterogeneous iron-based catalysts are widely used in dehydrogenation reactions, particularly, in the dehydrogenation of propane to propylene [9][10][11]. In some works, nanostructured Fe and Fe-Zn/Al 2 O 3 systems served as the catalysts for isobutane dehydrogenation [12,13]. In [14] it was reported that for Fe/SiO 2 catalysts, single iron sites embedded in a silica matrix were responsible for methane conversion exclusively to ethylene and aromatics.…”