Catalytic effect of platinum

Anderson AB, Albu TV. 2000. Catalytic effect of platinum on oxygen reduction—An ab initio model including electrode potential dependence. J Electrochem Soc 147 4229 -4238. 

Platinum. Other materials are effective promotors for the oxidative adsorption of SO2. Figure 6, for instance, demonstrates the effect of platinum which is the best promotor and the earliest one used for the UltraCat process (31). The figure, which compares SO2 removal curves for alumina alone and with 2 and 100 ppm Pt at 1200, 1300 and 1400 F, indicates that alumina promoted with platinum at both levels is more efficient for removing SO2 than pure alumina. The catalytic effect of platinum, not unexpectedly, becomes less pronounced as the temperature is increased as can be seen by inspecting the curves and also by comparing the percentage of SO2 removed after 100 minutes as shown on Table IV. 

The catalytic effect of platinum salts can be explained by the intermediate formation of an olefin-metal complex in which the electron density of the... 

The catalytic effect of platinum on the oxidation of cinnamyl alcohol... 

Jeguirim M, Tschamber V, Ehrburger P (1997) Catalytic effect of Platinum on the kinetics of carbon oxidation by NO2 and O2. Applied Catalysis B Environmental 76 235-240... 

The catalytic aerobic oxidation of alcohols has a long history dating back to Dbbereiner s observation, in 1820, that ethanol is oxidized to acetic acid over platinum black. Indeed, this preceded the coining of the term catalysis, by Berzelius in 1835 The catalytic effect of platinum on the aerobic oxidation of cinnamyl alcohol was described by Strecker in 1855" and in the period 1912-1921 Wieland showed that finely divided palladium catalyzes the aerobic oxidation of primary alcohols to aldehydes in aqueous... 

Sensors febricated in the Schottky diode configuration (using Pt as a metal catalyst) showed improved performances compared with standard thin film conductometric devices for hydrogen detection, especially in oxygen-rich environment. This has been ascribed to the catalytic effect of platinum for the chemisorption of hydrogen that also allows the sensor to work in a wide range of temperatures. 

Mass loss determinations refer to the total change resulting from reactant decomposition and usually include contributions from a mixture of product compounds, some of which would normally be condensed under conditions used for accumulatory pressure measurements. Such information concerned with the overall process is, however, often usefully supplemented by evolved gas analyses (EGA) using appropriate analytical methods. Sestak [130] has made a detailed investigation of the effects of size and shape of reactant container on decomposition kinetics and has recommended that the sample be spread as a thin layer on the surfaces of a multiple plate holder. The catalytic activity of platinum as a reactant support may modify [131] the apparent kinetic behaviour. 

Binder H, Kohling A, Sandstede G. 1972. Effect of alloying components on the catalytic activity of platinum in the case of carbonaceous fuels. In Sandstede G, ed. From Electrocatalysis to Fuel Cells. Seattle University of Washington Press, p. 43. 

Effect of Platinum Oxidation State in the Catalytic Oxidation of Cyclohexene... 

The analogous hydroxylation of alkynes to produce ketones is enhanced by the co-catalytic effect of Aliquat and platinum(IV) chloride-carbon monoxide [3] it is assumed that HPtCI(CO) is the active hydration species. C-S and C-Br bonds are cleaved under the reaction conditions. 

According to long-lasting experimental efforts, the use of alloy catalysts that contain a less noble metal whose oxide exhibits low solubilities in acid electrolytes—in particular Sn and Bi are effective in this respect—enhance the catalytic activity of platinum. The rationale of this effect has been that the oxide of the nonnoble component at close atomic distance from the Pt surface atoms supplies by spillover the oxygen that is necessary to oxidize the adsorbed CO species. Today research and development turn more to Ru and lr or Rh, the more easily oxidizable platinum metals as alloying metals that seem to be at least as efficient as Bi and Sn and are certainly more stable than those in acidic environments—in particular if the anode potential becomes more anodic in cases of poor supply of fuel (158). The Pt-Ru anode exhibits a sizeable higher oxidation current for methanol and for adsorbed hydrogen than the Pt electrode, indication that a smaller part of the Pt electrode surface is blocked by CO adsorption. Still the catalytic activity is too low because the onset of the anodic peak of methanol oxidation is at a... 

A systematic attempt to correlate the catalytic effect of different surfaces with their adsorptive capacity was made by Taylor and his collaborators. Taylor and Burns, for example, investigated the adsorption of hydrogen, carbon dioxide, and ethylene by the six metals nickel, cobalt, palladium, platinum, iron, and copper. All these metals are able to catalyse the hydrogenation of ethylene to ethane, while nickel, cobalt, and palladium also catalyse the reduction of carbon monoxide and of carbon dioxide to methane. 

The electrode potential exerts an important influence upon the course of the reduction, but there is undoubtedly a catalytic effect as well the latter is particularly evident with cathodes of copper or platinum. Lob4 and Haber8 consider that electrode potential is the determining factor, but Tafel6 emphasises the importance of the catalytic effect of the electrode material. Undoubtedly the product... 

The effect of lead adatoms on the catalytic activity of platinum, for the hydrogenation of maleic acid and methylsubstituted maleic acids, was determined (Fig.l),... 

The Cat, or its product of electrode oxidation or reduction Cat, is immobilized at the electrode surface and decreases the overpotential for oxidation or reduction of the S, without being involved in the chemical redox reaction with the S. Typical example is the catalytic effect of underpotential deposited layer of lead on a platinum electrode, on anodic oxidation of methanol [v]. 

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