Carbon modified

Sakthivel, S. and Kisch, H. (2003) Daylight photocatalysis by carbon-modified titanium dioxide. Angewandte Chemie International Edition, 42 (40), 4908-4911. 

ELECTROCHEMICAL ACTIVITY OF CARBONS MODIFIED BY d-METAL COMPLEXES WITH ETHANOLAMINES... 

Traces of copper and lead are separated [301] from macro amounts of calcium, magnesium, sodium, and potassium by adsorption from the sample onto active carbon modified with hydroxyquinoline dithizone or diethyldithiocarbamate. 

Bandosz TJ, Petit C. On the reactive adsorption of ammonia on activated carbons modified by impregnation with inorganic compounds,). Coll. Interface Science 2009, 338, 329-345. 

Apart from titanium oxide, two other carbon-modified semiconductors were studied in water photoelectrolysis due to their low band gap energy, namely iron (Fe203) and tungsten oxide (W03) [70,90]. Carbon-modified iron oxide demonstrated promising photoconversion efficiency, 4 % and 7 % for modified oxides synthesized in oven and by thermal oxidation respectively [90]. Also, carbon-modified tungsten oxide (C-W03) photocatalysts exhibited a 2 % photoconversion efficiency [70],... 

IPCE and APCE can have values close to 100%. As discussed before, the maximum attainable photoconversion efficiency in a single bandgap photoelectrolysis cell is 30.7%. Although stable, the photoconversion efficiencies of most oxide semiconductors are low (<2% except the case of 8.35% reported for carbon modified titania [121]) due to their large band gap. 

Trace mercury determination by differential pulse (dp) anodic stripping voltammetry on polythiophene-quinoline/glassy carbon modified electrode has been reported [77]. 

S. Sakthivel and H. Kisch, Daylight Photocatalysis by Carbon-Modified Titanium Dioxide, Angew. Chem. Int. Ed. 2003,42, 4908. 

In this paper, the results of the isomerization of hexane, heptane and octane over a Mo2C-oxygen-modified-catalyst, a Mo03-carbon-modified catalyst and a Pt//l-zeolite catalyst, at atmospheric pressure, are presented. Also, the results for a conventional Pt/Al203 catalyst are presented for the isomerization of hexane. Then, the effect of pressure on the isomerization of heptane and octane over the molybdenum catalysts and the Pt//l-zeolite catalyst is shown. Finally, the ability of the molybdenum catalysts to catalyse the isomerization reaction at high conversion with high selectivity even with hydrocarbons larger than hexane is demonstrated this is not possible over the Pt catalysts. The differences between the catalysts are discussed in terms of the reaction mechanisms. 

Comparison of the activity over the Mo03-carbon-modified catalyst, which as already mentioned, is the most active of the molybdenum catalysts, with that obtained for the Pt// -zeolite shows that the platinum is... 

The effect of pressure on the isomerization of n-heptane and n-octane was determined over the Pt//l-zeolite, Mo2C-oxygen-modified and M0O3-carbon-modified catalysts. The weight hour space velocity (WHSV) was changed with the pressure to keep the conversion at a similar level, enabling the effect on the isomerization selectivity and the product distributions to be seen. Other conditions were kept constant. 

The results for the isomerization of n-heptane are presented in Table 20.5. Over all the catalysts the main products are again the 2-methyl (M2H) and 3-methylhexanes (M3H), with a significant contribution from the dimethylpentanes of 12-13% over the platinum and Mo2C-oxygen-modified catalysts, and 21% over the Mo03-carbon-modified catalyst. 3-Ethylpentane always contributes around 3% to the isomer distribution and almost no cyclic products are observed. Increasing the pressure over the... 

Pt// -zeolite, Mo2C-oxygen-modified and Mo03-carbon-modified catalysts leads to a decrease in the ratio of the M2H/M3H isomers of 1.10 to 1.02, 0.92 and 0.87 to 0.71 respectively. 

Mc C-oxygen modified Mo03-carbon modified Pt//i-zeolite... 

Figure 20.7 Activation period for rc-heptane isomerization over Mo03-carbon-modified at...

We have tested the above hypothesis by investigating the activation of the C-H bonds of /z-butane and iso-butane and the C=C bonds of 1,3-butadiene, 1-butene and iso-butene on clean V(110) and on VC/V(110) surfaces by using HREELS and TDS.5 Figure 24.6 shows the TDS results following the reaction of/j-butane from clean and carbide-modified V(110) surfaces. For each set of TDS experiments, the clean and carbon-modified V(110) surfaces were exposed to identical exposures of /z-butane at 80 K. Desorption peaks from both parent molecules and the decomposition product (hydrogen) are compared. As shown in Figure 24.6, the adsorption of /z-butane on clean V(110) is completely reversible, as indicated by the absence of any H2 desorption peak. On the carbide-modified surfaces, the peak area of molecularly desorbed /z-butane decreases, which is accompanied by an increase in the peak area of H2 at approximately 500 K. Both observations indicate that the fraction of n-butane undergoing decomposition is increased on the carbide-modified surfaces. 

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