Nucleation and growth of carbon nanoforms on the surface of metallic plate-substrates and the mechanism of their doping with the clusters of ferromagnetic atoms  

Abstract

The present work deals with the special experiments on SEM-EDX study of morphology, chemical composition and topological transformations of the initial ground surface of the bulk iron plate-substrate after its interaction with the ethanol vapor pyrolysis products at high temperatures in the closed-loop and open cycle reactors. Our experiments have shown that the mechanism of formation of Fe clusters-doped CNFs on plate-substrate surfaces may be represented as a process, the first stage of which is a protonation of the substrate subsurface layers caused by diffusion of hydrogen atoms facilitating the formation of 3D nano-groups of Fe atoms assembled in the characteristic clusters with magic numbers of atoms, depending on the thermodynamics of the metal. The spontaneous coalescence of these clusters into giant Feclusters at comparatively low temperatures and formation of iron nano-droplets at comparatively high temperatures results in the formation of a nanopatterned surface with the uniformly distributed catalytic centers of CNFs nucleation. The second stage of the process is a nanoparticle-guided growth through the VLS or VS (at low temperatures) growth mechanisms in which the one cluster provides a nucleation of only one CNF particle so that the sizes of the nucleation centers determine the basic size of the CNF nanoparticles.

The Effect of Granulated Fe Cluster-doped CNTs Support on The Catalytic Performance of NiO Catalyst in the DRM Reaction

“…According to the aim of this research, for the preparation of a NiO-based catalyst system with the granulated Fe atom cluster-doped CNTs carrier, a sufficient amount of nanopowder of Fe atom cluster-doped CNTs has been synthesized using the experimental set-up providing the realization of the mechanism of doping of single CNTs with Fe atom clusters [19].…”

“…From this point of view, different carbon materials, especially their nanoforms such as carbon nanotubes (CNTs) and carbon nanowires (CNWs) have recently gained a continuously growing interest in a series of applications due to their unique properties. In particular, the thermal stability, high corrosion resistance, high specific surface area, and nano/meso-sized pore structure are thought to be interesting in terms of heterogeneous catalysis and electrocatalysis as a catalyst supporter (carrier) or as a catalyst itself [13][14][15][16] available in the direction of the application of carbon nanoforms doped with 3d metals' clusters [17,18], namely Fe atom cluster-doped CNTs [19], as the granulated carriers for various catalyst systems used in the DRM reaction. This is conditioned by the obstacles in the production of catalyst carriers in the form of granules (with suitable mechanical properties) from the nanopowder composed of Fe-atom cluster-doped CNTs nanoparticles using conventional methods of granulation.…”