Simple Hybrids Based on Mo or W Oxides and Diamines: Structure Determination and Catalytic Properties

Abstract

Crystalline hybrid catalysts based on molybdenum or tungsten oxide and aliphatic diamines were synthesized via simple, ecofriendly reproducible methodologies, starting from commercially available and relatively inexpensive organic and inorganic precursors, and using water as solvent under mild conditions. The crystal structures of the obtained fine powdered solids were solved ab initio from powder X-ray diffraction data. The type of organic component (1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopropane) may play a structure-directing role. On the other hand, different metals (M = Mo, W) may lead to isostructural one-dimensional hybrids of the type MO 3 (L) with the same bidentate diamine ligand L. The prepared catalysts were investigated for the liquid phase oxidation of saturated and unsaturated hydrocarbons (cis-cyclooctene, cyclooctane), using different types of oxidants (O 2 , H 2 O 2 , tert-butyl hydroperoxide). Differences in catalytic performances associated with distinct structural features were investigated. Graphic AbstractKeywords Hydrocarbons oxidation and epoxidation · Hybrid materials · Crystal structure determination · X-ray powder diffraction Electronic supplementary material The online version of this article (https ://doi.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Versatile Polyoxometalates of Different Structural Dimensionalities for Liquid Phase Catalytic Oxidation

“…The three models fitted the experimental data well. Hence, the discussed kinetic models for the Cy, Ole and Lin reactions were based on the assumptions for the simplest model, e.g., for Cy, the equations 1, 2 and 3 with the rate constant k Cy (h The oxidation of cyclooctane was experimentally performed as previously described [26,49,50]. The experiment was carried out in a stainless-steel batch reactor system at 120 • C and under an air pressure of 10 atm.…”

A Molybdenum(VI) Complex of 5-(2-pyridyl-1-oxide)tetrazole: Synthesis, Structure, and Transformation into a MoO3-Based Hybrid Catalyst for the Epoxidation of Bio-Olefins

“…TBHP may be produced from renewable sources, has a growing market with commercial applications such as the large-scale epoxidation of propene [38,39], and presents as main advantages its compatibility with organic media, stability, and the fact that the co-product is tert-butanol, which can be repurposed. Moreover, as discussed below, catalytic stability may be higher when using TBHP, whereas H 2 O 2 may promote the decomposition and solubilization of the molybdenum compounds [37,[40][41][42]. On the other hand, the hydrophobicity, relatively high boiling point (102 • C), and insignificant coordinating properties of TFT make it more appealing than volatile halogenated solvents, which contribute to atmospheric emissions (with damaging environmental impacts), or coordinating solvents, which may compete with the reactants for access to the active sites [43].…”