Development of a Technique and Investigation of Capacitance Characteristics of Electrode Materials for Supercapacitors Based on Nitrogen-Doped Carbon Nanotubes

Carbon nanotubes are widely employed as catalyst supports and electrode materials. In our earlier studies, capacitance characteristics of carbon nanotubes (CNTs) and nitrogen-doped carbon nanotubes (N-CNTs) were measured. Voltammetric curves obtained for nitrogen-doped nanotubes in an acid electrolyte showed pseudocapacitance peaks that were caused by electrochemical processes involving nitrogen-containing functional groups. In this study, measurements were made in a two-electrode cell of a supercapacitor with a hydrophilic polypropylene PORP-A1 film serving as a separator in alkaline (6 M KOH solution) and acid (1 M H2SO4 solution) electrolytes using a PARSTAT 4000 potentiostat/galvanostat. A technique was developed to estimate the contribution of electrical double layer (EDL) by subtracting pseudocapacitance from total capacitance of a cell using the Origin 9 software. The contribution of EDL and pseudocapacitance to the capacitance of supercapacitor cells was estimated. The highest capacitance of an electrode material equal to 97.2 F/g (including the EDL capacitance of 65 F/g) was reached for nanotubes doped with 8.5% of nitrogen in an acid electrolyte at a potential scanning rate of 10 mV/s

Highly Dispersed Palladium on Carbon Nanofibers for Hydrogenation of Nitrocompounds to Amines

The effect of palladium dispersion and nature of the support on catalytic performance in hydrogenation of nitrobenzene to aniline was studied. It was shown that the type of the support and modification of palladium with phosphorus make it possible to stabilize highly dispersed (1.5-2 nm) palladium particles in the metallic state, thus increasing the efficiency of new catalysts

On the role of carbon support in the catalytic wet peroxide and air oxidation of organic contaminants

SSCI-VIDE+CARE:CDFA+CDS:MBEInternational audienceNon

Ruthenium nanoparticles supported on nitrogen-containing carbon nanofibers for CWAO of phenol

SSCI-VIDE+CARE:CDFA+CDS:MBEInternational audienceNon

Ruthenium nanoparticles supported on nitrogen-doped carbon nanofibers for the catalytic wet air oxidation of phenol

EAU+CDS:MBEInternational audienceThe effect of nitrogen content in N-doped carbon nanofibers (N-CNFs) on the catalytic activity of Ru/N-CNFs in the wet air oxidation of phenol has been studied. The N-CNFs, irrespective of nitrogen content and Sibunit, are shown to be low active. In the case of Ru-containing catalysts, nitrogen in N-CNFs was found to be responsible for both the increased activity and stability of the catalysts toward deactivation. The XPS showed the formation of carbon-oxygen structures with hydroxyl (carbonyl) end groups blocking ruthenium on the surface of the catalysts without nitrogen. For the catalysts with nitrogen, the ruthenium nanoparticles were not blocked in the course of the reaction and mainly the carboxyl (carbonate) surface groups were formed. The nature of this effect is discussed. (C) 2013 Elsevier B.V. All rights reserved