Fullerene Black: Structure, Properties and Possible Applications

This review concerns the fullerene black, a poorly known nano-sized carbon material, the insoluble recidue after extraction of fullerenes from fullerene soot produced by arc evaporation of carbon material (usually graphite) in a helium atmosphere. This by-product of the production of fullerenes, whose yield reaches 80 wt %, is a finely dispersed material with a particle size of 40–50 nm. It includes amorphous carbon, graphitized particles, and graphite. Test reactions showed the presence in the structure of fullerene black of curved surfaces, and, like fullerenes, of alternating non-conjugated simple and double bonds. In addition to the double bonds, its structure includes dangling bonds in the concentration not higher than one per 1200 carbon atoms. This nano-carbon can not be graphitized, enters into the reactions of nucleophilic addition, graphite) in a helium atmosphere. This by-product of the production of fullerenes, whose yield reaches 80 wt %, is a finely dispersed material with a particle size of 40–50 nm. It includes amorphous carbon, graphitized particles, and graphite. Test reactions showed the presence in the structure of fullerene black of curved surfaces, and, like fullerenes, of alternating non-conjugated simple and double bonds. In addition to the double bonds, its structure includes dangling bonds in the concentration not higher than one per 1200 carbon atoms. This nano-carbon can not be graphitized, enters into the reactions of nucleophilic reinforces their surface. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3505

Nitrobenzene Hydrogenation to N-phenylhydroxylamine: a New Approach to the Selectivity

A new approach to resolve the problem of selectivity with respect to N-phenylhydroxylamine in nitrobenzene hydrogenation is proposed. N-phenylhydroxylamine only is the final product of nitrobenzene electroreduction in aprotic media. In this case nitrobenzene reduction carries out by alternation of electrochemical (electron transfer) and chemical (species formed protonation) stages i.e. by so-called EC mechanism. Such mechanism realization in nitrobenzene hydrogenation is possible if i) a catalyst activates hydrogen as “hydrogen electrode” i.e. serves electrons source; ii) a reaction media contains limiting proton concentration. These limitations are discharged in the media of aprotic dipolar solvent, which solvated both positive and negative species. Really, in aprotic dipolar solvents over reduced platinum complexes or lowpercentage (≤1 wt.%) platinum, iridium or osmium catalyst nitrobenzene is hydrogenated with process discontinuance after nitrobenzene total consumption. Nitrobenzene hydrogenation yields N-phenylhydroxylamine as the main (the yield is 98%) product. As these low-percentage catalysts, complex catalyst in situ is heterogeneous i.e. it represents a platinum colloid (particle size ~ 40 nm) stabilized by aprotic dipolar solvent. So, process of nitrobenzene hydrogenation, which is similar to nitrobenzene electoreduction, can is created. A kinetic scheme proposed is analyzed and kinetic equation for initial reaction rate, which is conformed to kinetic data, is obtained

Pt supported on reduced graphite oxide catalysts for H2 activation

Platinum catalysts of H2 activation with average size ≤2.0 nm were prepared in a base of reduction conversion of graphene oxide. A low few-layered carbon nanomaterial was prepared by thermoexpansion and annealing of graphene oxide. The uniformly dispersed Pt nanoparticles were supported on two-dimension graphene flat material by the use of pyridine or polyethyleneimine in alkaline (pH10) media as chelating agent modificating both metal precursor H2PtCl6 and support. Vacancies in carbon material formed as a result of thermoexpansion and annealing of graphite oxide probablly serve as anchor groups in platinum supporting. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3557

Platinum Nanoparticles Supported on Reduced Graphite Oxide as Hydrogenation Catalyst

Platinum nanoparticles supported on reduced graphite oxide are produced by reduction of a slurry including graphite oxide and H2PtCl6·xH2O, and pyridine as modifying agent. Four compounds as a formation formateion decene-1 and nitrobenzene hydrogenation at hydrogen atmospheric pressure and 45°C. In the result of reduction Pt4+ is converted to Pt metal and graphite oxide loses of oxygen. The symbasis Pt loading with C/O ratio is observed. Compositions Pt - reduced graphite oxide catalyze the hudrogenation of decene-1 and nitrobenzene in a solution. The greatest activity is shown composition reduced by sodium borohydride with the particle size of 2.0 nm, however it is substantially lower than it for Pt/fullerene black catalyst. Some inhibiton of hydrogenation by incompletely reduced graphite oxide is shown. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3505