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Abstract  

The influence of trace oxygen on the catalytic activity of alumina supported Ru in the liquid phase hydrogenation of aromatic hydrocarbons was studied. The catalytic activity of Ru increased remarkably and the reproducibility was improved by removing dissolved oxygen from the reactant mixture and carefully refining the catalyst transfer procedure into the reactor to avoid exposure to air. Trace oxygen affected Ru very severely, but did not affect Rh, Pd, and Pt much. The activity of Ru was lower than those of Rh, Pd, and Pt in the presence of oxygen as reported in the literature; however, it was the highest when oxygen was removed carefully. Measurements of the adsorbed oxygen suggested that the activity seriously decreased when only the part of Ru surface was covered by oxygen. Bimetallic Pt–Ru catalysts demonstrated high activity even in the presence of oxygen.

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For a standard test, 0.05 g Ru catalyst was pretreated in a 40 mL/min hydrogen flow at 623 K for 1 h before use. The catalyst was then mixed with 20 mL water containing substrate and transferred to a 100 mL autoclave. The hydrogenation reaction began

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Abstract  

Ruthenium catalysts have been prepared by incipient wetness impregnation of ruthenium(III) nitrosylnitrate, Ru(NO)(NO3)3 onto high surface area titanate supports obtained by hydrothermal treatment of TiO2 P25 in concentrated alkaline solutions. These Ru-containing catalysts were evaluated in the catalytic wet air oxidation of p-hydroxybenzoic acid (p-HBZ), a model compound representative of phenolic pollutants present in olive mills wastewaters, at 413 K and 50 bars of air. Two different titanates morphologies were tested as supports for this reaction: hydrogenotitanate nanotubes (HNT) obtained with concentrated NaOH and hydrogenotitanate nanowires (HNW) formed in the presence of highly concentrated KOH solution. The HNT and HNW supports and their corresponding supported Ru catalysts were characterized by means of N2 adsorption–desorption, XRD, UV and TEM analyses. Results showed that the use of high surface area titanate supports led to catalysts much more active than similar Ru catalysts supported on conventional TiO2 supports.

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Abstract  

In this work, hydrogenation of sorbic acid to cis-hex-3-enoic acid using homogeneous Ru catalyst [Cp*Ru(sorbic acid)]Tf (Tf = CF3SO3 ) immobilized to smectite materials by means of ion exchange has been studied. The immobilized catalyst was utilized for heterogeneous hydrogenation of sorbic acid to the desired cis-hex-3-enoic acid, achieving the selectivity of up to 95% and the possibility of the catalyst to be reused.

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Journal of Flow Chemistry
Authors: Gary Perkins, Omar Khatib, Matthew Peterson, Annukka Kallinen, Tien Pham, Alison Ung, Ivan Greguric, and Giancarlo Pascali

Carbon dioxide chemistry is an area of continuing growth in recent times, due to socioeconomic and environmental reasons. Several methods have now been reported for obtaining N-methylation on primary and secondary amines directly from CO2. We have translated in two microfluidic setups (Slug Flow [SF] and Tube-in-Tube [TiT]) a ruthenium (Ru)-catalyzed process previously reported using a pressure vessel. Here, we demonstrate how the SF approach is more efficient but requires more input to reach a steady state, while the TiT system is less efficient but more tuneable.We have tested these processes on three model amines and two radiopharmaceutical precursors that are routinely used in 11C chemistry. The microfluidic processes tested are also potentially more efficient than the pressure vessel counterpart, in terms of amount of Ru catalyst needed (1% vs. 10%) and projected reaction completion time.

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. Fig. 1 shows the TOC abatement as a function of time on stream obtained in the continuous reactor packed with the supported Ru catalysts at 140 and 150 °C. Fig. 1 TOC conversion as a function of time on stream

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is usually higher than predicted, particularly over Co and Ru catalysts. C2 and C3 are produced less than predicted by ASF. This is supported by ethene and propene being able to polymerize quickly to heavy FT products over a Co catalyst in the

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Reaction Kinetics, Mechanisms and Catalysis
Authors: R. Thinesh Kumar, N. Clament Sagaya Selvam, T. Adinaveen, L. John Kennedy, and J. Judith Vijaya

. The selectivity for benzaldehyde was more than 99%. The byproduct of benzoic acid was not detected. The carbon balance was close to 100%. Though there are precious metal-based Pd and Ru catalysts [ 41 – 43 ], which usually achieved 100% conversion of

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