Multiwalled carbon nanotubes (CNTs) were synthesized by catalytic pyrolysis of methane on iron-cobalt or cobalt-molybdenum catalyst and investigated by electrochemical and physico-chemical methods before and after chemical or electrochemical corrosion treatment. It is shown that CNTs have a higher corrosion resistance than does turbostratic carbon (carbon black) in corrosion testing under the same conditions. This is expressed in a smaller change in the amount of oxygen on the surface of the carbon material, the values of the electrochemically active surface area (EAS), and in significant differences of these quantities for the CNTs compared to carbon black. Quantitative comparison of the results of chemical and electrochemical treatment of CNT and carbon black, which was performed in this paper for the first time, leads to the conclusion regarding the advantages of corrosion testing by chemical method. Chemical testing simulates to a greater extent the long-term testing conditions of the supported catalysts composed of membrane-electrode assemblies of fuel cells in terms of evaluating the stability of the carbon material as a support of the catalytically active centers.

Проведено экспериментальное исследование кинетических закономерностей синтеза углеродных нанотрубок каталитическим пиролизом метановодородной смеси переменного состава на железо-кобальт-алюминиевых катализаторах. Оценено влияние температуры, состава и количества активной фазы катализатора, а также состава газовой атмосферы на выход и качество углеродных нанотрубок. Наиболее однородные по внешнему диаметру углеродные нанотрубки (10–20 нм) получены на катализаторе с 60 % активной фазы (Fe:Co = 3:1). При разбавлении метана водородом меняется характер активности катализатора, при этом зависимость выхода углерода от содержания водорода в смеси имеет экстремальный характер с максимумом при 40 % об. водорода. В результате исследования установлено, что наибольший выход углеродных нанотрубок внешним диаметром 10–30 нм получен на катализаторе с 60 % активной фазы при пиролизе метановодородной смеси с содержанием водорода 40 % об.

The scientific work is devoted to mathematical modeling of heterotrophic microalgae cultivation in a fed-batch bioreactor with aeration and mechanical mixing. The multiphase mathematical model, taking into account processes in a cell and on the cell-nutrient medium bound, was developed. By means of analyses of the experiment results it was shown that growth characteristic change takes place after glucose addition in the fed-batch bioreactor. Regularities of these changes were revealed.

The modeling the synthesis kinetics of carbon nanotubes and nanofibers by means of methane catalytic decomposition process was carried out. Programs were developed which allow obtaining an information on the concentration of every compound taking place in the pyrolysis process in any moment of time in any position in the reactor. Also, programs allow simulating the growth and formation of nanotubes and nanofibers of different structure.