Graphite, catalysts

Figure 2. Example of a topographic image of Pt/Graphite catalyst.

Figure 13. Shapes observed on a Pt/Graphite catalyst after a methanation reaction at 850°C.

Oxidation of Highly Dispersed Platinum on Graphite Catalysts in Gaseous and Aqueous Media... 

Catalyst. A highly dispersed platinum on graphite catalyst was prepared following a method described by Richard and Gallezot 20). 

These results indicate that the same crystalline face does not necessarily exhibit the same catalytic properties with different molecules. Thus, the (010) face of a-Mo03 is selective for the formation of aldehydes from alcohols while it promotes essentially the deep oxidation of olefins. It is expected that the studies on structure-sensitive reactions will be made more quantitative using recent methods to determine the number of surface M=0 species (425 —7). It should be noted that the earlier observation on the specificity of Mo03 crystalline faces in propylene oxidation has been obtained on oriented Mo03-graphite catalysts (425k). Non-structure-sensitive reactions have also been reported (425k). 

Volta, J. C, Desquesnes, W., Moraweck, B., and Coudurier, G., A new method to obtain supported oriented oxides M0O3 graphite catalysts in propylene oxidation to acrolein, React. Kinet. Catal. Lett. 12, 241 (1979). 

Table 1. Fraction platinum atoms exposed as determined with CO chemisorption (FE00) and cyclic voltammetry (FE ) for a 3.35 wt% Pt/graphite catalyst used in the ethanol oxidation at 298 K and MGP oxidation at 323 K. Conditions C°eth(ino,=100 mol/m3 C°MQP= 100 mol/m3, Q - 2.5 kg/m3, pH-8.0.

It has recently been found42 that Au/C and Au/graphite catalysts are effective for the aerobic oxidation of other alkenes at 353 K small amounts of either hydrogen peroxide or tert-butylhydroperoxide ( BuOOH) are needed as oxygen chain initiators. The products of the reactions of cyclohexene,... 

Hydrazine hydrate can also be used to reduce nitroalkanes in the presence of a graphite catalyst. " The low cost of the catalyst serves to make this a particularly attractive reduction method. Electrochemical reduction of tertiary nitroalkanes such as the 2-substituted-I,l-dimethyl-l-nitroethanes (42a-42c) yields amines (44a-44c) as well as hydroxylamines (43a-43c equation 27). ... 

In general, Pt/C catalysts show little selectivity in the hydrogenation of the carbonyl group of a,P-unsaturated aldehydes but a Pt/graphite catalyst promoted the hydrogenation of cinnamaldehyde at 60°C and 40 atmospheres in an aqueous iso-propyl alcohol solution containing some sodium acetate. Cinnamyl alcohol was obtained in 83% selectivity at 50% conversion. Comparable selectivities... 

Potassium-on-alumina or a lamellar K-graphite catalyst promotes total hydrogenation of benzene rings. Carbocyclic and heterocyclic aryl rings are reducible with... 

G.C. Stevens and T. Edmonds, Preparation and properties of thiomolybdate graphite catalysts, in Preparation of catalysts II (eds, B Delmon,... 

Polycinnamamide has been synthesized by use of the Heck reaction catalyzed by a recyclable Pd-graphite catalyst [19a], Because the catalyst is easily separated from the reaction mixture, the Pd content of the polymer can be lower and the polymer is less colored polymerization is more selective than when homogeneous catalysis is used [19b]. 

Figure 2 Conversion of CAM and selectivity to products for the hydrogenation of CAM over an un-reduced 5% Ir/graphite catalyst. Reaction conditions P 20 bar H2, T 100 °C, reaction time 5 hours...

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