Selective hydrogenation of carboxylic acids to alcohols and alkanes has been achieved under remarkably mild reaction temperatures and H(2) pressures (333 K, 0.5 MPa) using Pt/TiO(2) catalyst.

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Organic solvents, such as cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene, are widely used as both reagents and solvents in industrial processes. Despite the ubiquity of these liquids, the local structures that govern the chemical properties have not been studied extensively. Herein, we report neutron diffraction measurements on liquid cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene at 298 K to obtain a detailed description of the local structure in these compounds. The radial distribution functions of the centres of the molecules, as well as the partial distribution functions for the double bond for cyclohexene and methyl group for methylcyclohexane and toluene have been calculated. Additionally, probability density functions and angular radial distribution functions were extracted to provide a full description of the local structure within the chosen liquids. Structural motifs are discussed and compared for all liquids, referring specifically to the functional group and aromaticity present in the different liquids.

Stable chromium, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, and iridium metal nanoparticles (M-NPs) have been reproducibly obtained by facile, rapid (3 min), and energy-saving 10 W microwave irradiation (MWI) under an argon atmosphere from their metal-carbonyl precursors [M(x)(CO)(y)] in the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF(4)]). This MWI synthesis is compared to UV-photolytic (1000 W, 15 min) or conventional thermal decomposition (180-250 degrees C, 6-12 h) of [M(x)(CO)(y)] in ILs. The MWI-obtained nanoparticles have a very small (<5 nm) and uniform size and are prepared without any additional stabilizers or capping molecules as long-term stable M-NP/IL dispersions (characterization by transmission electron microscopy (TEM), transmission electron diffraction (TED), and dynamic light scattering (DLS)). The ruthenium, rhodium, or iridium nanoparticle/IL dispersions are highly active and easily recyclable catalysts for the biphasic liquid-liquid hydrogenation of cyclohexene to cyclohexane with activities of up to 522 (mol product) (mol Ru)(-1) h(-1) and 884 (mol product) (mol Rh)(-1) h(-1) and give almost quantitative conversion within 2 h at 10 bar H(2) and 90 degrees C. Catalyst poisoning experiments with CS(2) (0.05 equiv per Ru) suggest a heterogeneous surface catalysis of Ru-NPs.

The selective hydrogenation of α,β‐unsaturated aldehydes and ketones has been studied using ketoisophorone and cinnamaldehyde as model substrates using manganese oxide octahedral molecular sieve (OMS‐2) based catalysts. For the first time, OMS‐2 has been shown to be an efficient and selective hydrogenation catalyst. High selectivities for either the CC or CO double bond at ≈100 % conversion were achieved by using OMS‐2 and platinum supported on OMS‐2 catalysts. Density functional theory (DFT) calculations showed that the dissociation of H2 on OMS‐2 was water assisted and occurred on the surface Mn of OMS‐2(0 0 1) that had been modified by an adsorbed H2O molecule. The theoretically calculated activation barrier was in good agreement with the experimentally determined value for the hydrogenation reactions, indicating that H2 dissociation on OMS‐2 is likely to be the rate‐determining step. A significant increase in the rate of reaction was observed in the presence of Pt as a result of the enhancement of H2 dissociative adsorption and subsequent reaction on the Pt or spillover of the hydrogen to the OMS‐2 support. The relative adsorption strengths of ketoisophorone and cinnamaldehyde on the OMS‐2 support compared with the Pt were found to determine the product selectivity.

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Porcine pepsin was immobilized inside the SBA-15 mesoporous silica system through physical adsorption. A grafting step with 3-aminopropryltriethoxysilane (APTES) was performed to reduce the pore openings of the host material, in order to minimize the enzyme leaching. A detailed physical chemical characterization of hybrid materials was performed. The catalytic activity of the hybrid bioinorganic material, tested with two different substrates (hemoglobin and Z-l-glutamyl-l-tyrosine dipeptide), confirmed that pepsin was located inside the pore/channels of the silica material and that the grafting process did not affect the enzyme structure. The immobilized pepsin has maintained the necessary degree of freedom to fulfill its catalytic activity. The reusability of the so-called bioreactor was also investigated.

Two stable nanofluids comprising of mixed valent copper(I,II) oxide clusters (<1 nm) suspended in 1-butyl-3-methylimidazolium acetate, [C(4)mim][OAc], and copper(II) oxide nanoparticles (<50 nm) suspended in trioctyl(dodecyl)phosphonium acetate, [P(8 8 8 12)][OAc], were synthesised in a facile one-pot reaction from solutions of copper(II) acetate hydrate in the corresponding ionic liquids. Formation of the nanostructures was studied using (13)C NMR spectroscopy and differential scanning calorimetry (DSC). From a solution of Cu(OAc)(2) in 1-ethyl-3-methylimidazolium acetate, [C(2)mim][OAc], crystals were obtained that revealed the structure of [C(2)mim][Cu(3)(OAc)(5)(OH)(2)(H(2)O)]·H(2)O, indicating the formation of copper hydroxo-clusters in the course of the reaction. Synthesised nanostructures were studied using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Physical properties of the prepared IL-nanofluids were examined using IR and UV-VIS spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and densitometry.