Supported ruthenium catalyst

Figure 2. A comparison of the rate (turn-over frequency) of methane synthesis over single crystal and supported ruthenium catalysts. Total reactant pressure for the single crystal studies was 120 Torr.

Supported (alumina, silica) Ru catalysts The Mossbauer data show that RuCl3 (l-3)H20 reacts chemically when supported onto alumina, but does not when impregnated on a silica support. The study further shows that a supported ruthenium catalyst converts quantitatively into RUO2 upon calcination, and that the reduction of a supported ruthenium catalyst converts all of the ruthenium into the metallic state... 

Prior to the first hydrogenation batches, the supported ruthenium catalysts were reduced in the autoclave under hydrogen flow at 200°C for 2 hours (10 bar H2, heating/cooling rate 5°C/min). As the catalyst had been reduced, a lactose solution saturated with hydrogen was fed into the reactor rapidly and the hydrogen pressure and reactor temperature were immediately adjusted to the experimental conditions. Simultaneously, the impeller was switched on. This moment was considered as the initial starting point of the experiment. No notable lactose conversion was observed before the impeller was switched on. 

More recently, Chang reported a ruthenium-based Heck-type reaction in DME/H20 (1 1) by using alumina-supported ruthenium catalysts.154... 

Partial hydrolysis of nitrile gives amides. Conventionally, such reactions occur under strongly basic or acidic conditions.42 A broad range of amides are accessed in excellent yields by hydration of the corresponding nitriles in water and in the presence of the supported ruthenium catalyst Ru(0H)x/A1203 (Eq. 9.19).43 The conversion of acrylonitrile into acrylamide has been achieved in a quantitative yield with better than 99% selectivity. The catalyst was reused without loss of catalytic activity and selectivity. This conversion has important industrial applications. 

Baruwati, B., Polshettiwar, V. and Varma, R.S. (2009) Magnetically recoverable supported ruthenium catalyst for hydrogenation of alkynes and transfer... 

Basinska, A., and Domka, F. 1997. The influence of alkali metals on the activity of supported ruthenium catalysts for the water-gas shift reaction. Catal. Lett. 43 59-61. 

K. Yamaguchi, N. Mizuno, Supported Ruthenium Catalyst for the Heterogeneous Oxidation of Alcohols. Chem. 41 (2002) 4538-4531. 

Supported ruthenium catalysts prepared from Ru3(CO),2 have been used in CO hydrogenation because of the highly dispersed metallic phase achieved when this carbonyl-precursor is used [70,107-109]. However, under catalytic reaction conditions the loss of ruthenium from the support could take place, ft has been reported that at low temperatures it takes place through the formation of Ru(CO)s species, whereas at high temperature dodecarbonyl formation occurs [110]. Decarbonylation of the initial deposited carbonyl precursor under hydrogen could minimize this problem [107]. 

Aqueous solutions of 3-hydroxypropanal were reduced using Ti02 supported ruthenium catalysts at 40-60 °C using 40 bar of hydrogen. The most stable catalysts were found to be ruthenium catalysts supported on low surface area macroporous rutile. 

Our initial work on the TEMPO / Mg(N03)2 / NBS system was inspired by the work reported by Yamaguchi and Mizuno (20) on the aerobic oxidation of the alcohols over aluminum supported ruthenium catalyst and by our own work on a highly efficient TEMP0-[Fe(N03)2/ bipyridine] / KBr system, reported earlier (22). On the basis of these two systems, we reasoned that a supported ruthenium catalyst combined with either TEMPO alone or promoted by some less elaborate nitrate and bromide source would produce a more powerful and partially recyclable catalyst composition. The initial screening was done using hexan-l-ol as a model substrate with MeO-TEMPO as a catalyst (T.lmol %) and 5%Ru/C as a co-catalyst (0.3 mol% Ru) in acetic acid solvent. As shown in Table 1, the binary composition under the standard test conditions did not show any activity (entry 1). When either N-bromosuccinimide (NBS) or Mg(N03)2 (MNT) was added, a moderate increase in the rate of oxidation was seen especially with the addition of MNT (entries 2 and 3). 

This work was supported by the National Science Foundation under grant CHE8718850. This material is based upon work supported under a National Science Foundation Graduate Fellowship. We thank Prof. Bernard C. Gerstein for discussions pertaining to Cl ion contamination of supported ruthenium catalysts. 

Comparison of Initial Methanation Activities for Zeolite and Alumina Supported Ruthenium Catalysts... 

From the data presented in the following tables, determine the rates of ammonia synthesis (moles NH3 produced per min per gcat) at 350°C over a supported ruthenium catalyst (0.20 g) and the orders of reaction with respect to dinitrogen and dihydrogen. Pressures are referenced to 298 K and the total volume of the system is 0.315 L. Assume that no ammonia is present in the gas phase. 

The addition of MgO to activated carbon-supported ruthenium catalysts in an optimal Ru Mg ratio results in efficient catalyts for the CO2 reforming of methane, with stable selectivities towards CO and H2 production. 

Suzuki, T., Iwanami, H.-I., Iwamoto, O., and Kitahara, T. Pre-reforming of liquefied petroleum gas on supported ruthenium catalyst. International Journal of Hydrogen Energy, 2001, 26 (9), 935. 

Lanza R, Jaras SG, Canu P (2007) Partial oxidation of methane over supported ruthenium catalysts. Appl Catal A-Gen 325(l) 57-67... 

Synthesis and characterization of carbon nanoflber supported ruthenium catalysts... 

Homogeneous deposition precipitation (HDP) is explored for the preparation of carbon nanofiber supported ruthenium catalysts. First, carbon nanofibers (CNF, 177 m /g) are oxidized using nitric acid thus activating the graphitic carbon surfiice. Second, ruthenium (hydr)oxide is deposited homogeneously onto the CNF by hydrolysis of urea at 363K. 

The great potential of CNF as catalyst support material is demonstrated by several researchers. Metals like Pt [2], Pd [3,4] and Ni [58] are applied on CNF and tested in various reactions, a.o., selective hydrogenations. Selective hydrogenation reactions are important for the fine chemical industry. Ruthenium is one of the active metals for this reaction. Its performance is sensitive to subtle changes in dispersion and nature of the support. In this study we have applied ruthenium on a CNF support. For CNF supported ruthenium catalysts much higher selectivities (up to 92%) to cinnamylalcohol were found... 

The loading of the CNF supported ruthenium catalysts are studied with ICP-AES and turned out to be the aimed 5 wt%. This indicates that not all ruthenium is applied via ion-exchange, because using this method a loading of about 3 wt% can be obtained with CNF as support. 

TPR is used to obtain information on the reduction behavior of the catalysts. The results showed that the CNF supported ruthenium catalysts can be reduced at 473 K. The reduction temperature is higher than for bulk Ru02. If it is assumed that all ruthenium was present in the original catalyst as Ru02, a theoretical maximum H2/RU ratio of 2 should be observed. The ratios calculated from the TPR profiles of the catalysts are given in Table 1. 

In this manuscript, the third factor was studied by sulfur K-edge X-ray absorption near-edge structure (XANES). Infrared absorption spectroscopy is often used to monitor the adsorbed/intermediate species on the surface. However, by infrared absorption, the atoms dissociated from reactant molecules that are buried into the catalysts are often inaccessible, e.g. sulfur atom of SO dissociated and reacted to form the RuS phase. The major objective of this paper is to monitor both adsorbed and buried sulfur atoms by S K-edge XANES in the preparation process of supported ruthenium catalysts. 

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