Authors:Haruka Seki, Masa-aki Ohshima, Hideki Kurokawa, and Hiroshi Miura
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.
Authors:Liying Song, Kaixiang Li, Xiaohong Li, and Peng Wu
For a standard test, 0.05 g Rucatalyst 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
Authors:Mohamed Triki, Hafedh Kochkar, Gilles Berhault, and Abdelhamid Ghorbel
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.
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.
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.
Authors:Mohamed Triki, Anton Dafinov, Jordi Llorca, and Francisco Medina
Fig. 1 shows the TOC abatement as a function of time on stream obtained in the continuous reactor packed with the supported Rucatalysts at 140 and 150 °C.
TOC conversion as a function of time on stream
Authors:Seung-Ho Kwack, Myung-June Park, Jong Wook Bae, Kyoung-Su Ha, and Ki-Won Jun
is usually higher than predicted, particularly over Co and Rucatalysts. 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
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 Rucatalysts [ 41 – 43 ], which usually achieved 100% conversion of