Hydrogenation surface carbon

Results indicate that deposition is facilitated on active (copper, NijCr) compared to inert substrates. This is attributed to an easier decomposition of the precursor on copper or NijCr rather than on glass or carbon surfaces. Hydrogen can be dissociatively adsorbed on NijCr substrates enhancing the decomposition of NiCp. On copper substrates, the dissociative adsorption of hydrogen is not easy. In that case, the enhanced nucleation is certainly due to the... 

Fig. 3. CPK (Corey-Pauhng-Koulton) rendering displaying shaded soHd surface for ranitidine, normally color-coded according to atom types (black representing carbon green, hydrogen yellow, sulfur blue, nitrogen and red, oxygen colors not shown here).

Catalysis. Catalytic properties of the activated carbon surface are useful in both inorganic and organic synthesis. For example, the fumigant sulfuryl fluoride is made by reaction of sulfur dioxide with hydrogen fluoride and fluorine over activated carbon (114). Activated carbon also catalyzes the addition of halogens across a carbon—carbon double bond in the production of a variety of organic haUdes (85) and is used in the production of phosgene... 

Nitric acid treatment lowered the methane uptake by about ten percent. This could be due to oxygen occupying sites within pores, but may be the result of weaker interaction between methane and an oxide surface as is observed for silica. Reduction of these treated carbons with hydrogen restored their original methane uptake. Clearly for methane storage, there is no advantage in modifying the carbon surface by nitric acid treatment. 

D.A. Wesner, F.P. Coenen and H.P. Bonzel, Influence of potassium on carbon monoxide hydrogenation over iron A surface analytical study, Langmuir 1, 478-487 (1985). 

ERDA (HFS) only requires the addition of a thin foil (of carbon, mylar or aluminium) to separate forward scattered hydrogen from forward scattered primary He++ ions. The analytical information obtained consists of hydrogen concentration versus depth. The sample is tilted so that the He++ beam strikes at a grazing angle, giving a HFS depth profile resolution of about 50 nm. The surface hydrogen content... 

The initial step of the adsorption of cyclic sulfides on a Mo(100) surface is also the formation of adsorbed thiolate groups.395-397 Adsorbed alkyl thiolates decompose to adsorbed sulfur, carbon, and hydrogen on the clean Mo surface, but once the surface is deactivated by adsorbed sulfur, alkanes and alkenes evolve from the surface. Tetrahydrothiophene (34) and trimethylene sulfide decompose on Mo(110) to alkanes and alkenes by way of a common intermediate, which is proposed to be a surface thiolate (33). The thiolate undergoes hydrogenation or dehydrogenation, depending on the surface hydrogen concentration (Scheme 4.115).398 399... 

This is followed by a series of surface stepwise dissociation reactions leading to elemental carbon and hydrogen (the stepwise mechanism was suggested for Ni-catalyzed methane decomposition in Refs 100 and 122) ... 

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