Water is the most abundant molecule found in interstellar icy mantles. In space it is thought to be efficiently formed on the surfaces of dust grains through successive hydrogenation of O, O2 and O3. The underlying physico-chemical mechanisms have been studied experimentally in the past decade and in this paper we extend this work theoretically, using Continuous-Time Random-Walk Monte Carlo sim...

The kinetics and reaction network of hydrodemetallation (HDM) reactions and the pattern of metal deposition have been investigated using a model residuum oil, consisting of nickel porphyrins (Nietioporphyrin (Ni-EP), Ni-tetraphenylporphyrin (Ni-TPP), and Nitetra(3-methylphenyl)porphyrin (Ni-T3MPP)) dissolved in a clean (N and S free) mineral oil. Reactions were carried out over a commercial CoO...

• ZrO 2 @HKUST-1 composite was calcined to prepare Cu-ZrO catalysts with Cu nanoclusters. The catalyst significantly improved space time yield of CH 3 OH CO hydrogenation. is 5.2 times higher than reported under similar conditions. Controlled formation more interfaces that enhance activation. Pathways for the product and by-products are revealed via DFT calculations. In this study, a series hig...

The ethylene hydrogenation activity is compared for molybdenum oxycarbides, molybdenum carbides and a molybdenum alloy formed by reaction of molybdenum hexacarbonyl with alumina in ultrahigh vacuum using temperature-programmed desorption. It is found that molybdenum oxycarbides are inactive for ethylene hydrogenation. It is shown by forming carbides by reaction between alumina and ethylene that...

Frustrated Lewis pair (FLP) chemistry, a concept that has emerged in the last decade, presents unique systems capable of metal-free hydrogenation by using simple combinations of cooperative main group element components. This finding is particularly interesting given that hydrogenation is a chemical reaction that is performed on a huge scale worldwide with current technologies relying on metal-...

Since nanoscale gold was first discovered to be catalytically active, gold-based catalysts have been studied both theoretically and experimentally in a wide range of reactions. These catalysts exhibit high activity for hydrogenation processes, in particular showing enhanced selectivity. However, there is a lack of relevant fundamental studies into these processes. Conducting hydrogenation react...

Density functional theory (DFT) and infrared spectroscopy results are combined with mechanism-based rate equations to assess the structure and thermodynamics of chemisorbed CO (CO*) and its activation during Fischer-Tropsch synthesis (FTS). CO* binding becomes weaker with increasing coverage on Ru(0001) and Ru201 clusters, but such decreases in binding energy occur at higher coverages on Ru201 ...

Simple and complex organic molecules (COMs) are observed along different phases of star planet formation have been successfully identified in prestellar environments such as dark translucent clouds. Yet the picture molecule at those earliest stages is not complete an important reason lack specific laboratory experiments that simulate carbon atom addition reactions on icy surfaces interstellar g...

Z. Naturforsch. 50b, 315-325 (1995); received September 7, 1994 Oxadiene Complex, Molybdenum, Tungsten, X-Ray, Selective Hydrogenation Homoleptic tris(l-oxa-l,3-diene)molybdenum and tungsten complexes are formed as yel­ low, crystalline compounds in 54-80% isolated yield on treatment of the corresponding /3-unsubstituted a,/3-unsaturated ketones with W(CO)3(CH3CH2CN)3 or (y6-C6H6)Mo(CO)3 in ref...

Hydrogenation of oils might be considered as the largest reaction in the edible oil industry. The reaction consists of the addition of hydrogen at the double bounds of fatty acids. Although for some reasons this might be considered a desirable reaction but for some others it might create problems in the food and nutrition chain circle due to the formation of saturated and trans fatty acids. Soy...