The preparation of Al2O3/M (Fe, Co, Ni) nanocomposites by mechanical alloying and the catalytic growth of carbon nanotubes

The Growth of Carbon Nanostructure on the Mechanical-Milling-Derived Catalyst Precursors

“…According to chemical shift and quadrupole splitting parameters, for both F4 and F20 samples, the calcination at 800 o C gave rise to monophased Al 2-x Fe x O 3 solid solution, denoted Al 1.95 Fe 0.05 O 3 and Al 1.75 Fe 0.25 O 3 respectively. Therefore, the enhanced solubility of α-Fe 2 O 3 in Al 1.75 Fe 0.25 O 3 suggests the activation effects presented by the mechanical alloying [6]. For F20 sample, the segregation of α-Fe 2 O 3 phase took place after annealing at 1200 o C, indicating the instability of as-formed non-equilibrium Al 1.75 Fe 0.25 O 3 solid solution phase at high temperature.…”

“…To solve these problems, water-soluble stable ionic salts such as NaCl are good candidates as the matrix materials. Further to our previous works [5][6][7], in this work, we present detailed studies on the alloying effects, structure and phase evolution during mechanical milling and the subsequent thermal treatment. We investigated the reduction behaviors of different Al 2 O 3 /Fe 2 O 3 nanocomposites and their effects on the morphologies of as synthesized CNTs.…”

Electrochemical synthesis of nanosized iron oxide–alumina system

“…In the field of environmental protection, these materials are used as sorbents and agents in water and wastewater treatment, for example to reduce and remove phosphate ions [1,2], bromate ions [3], and other ions such as Ni 2+ , NH 4 + [2], Cr 6+ [4], and Hg 2+ [5]. Nanocomposites based on a mixed oxide system Al 2 O 3 -Fe 2 O 3 exhibit catalytic activity and selectivity in the oxidation and decomposition reactions of various organic pollutants [6,7], in the Fischer-Tropsch synthesis [8,9], and in technologies for producing carbon nanotubes [10,11].…”

“…There are several successfully realized methods for the synthesis of complex oxide system Al 2 O 3 -Fe 2 O 3 such as mechanochemical [10] and chemical methods based on precipitation from aqueous salt solution and subsequent hydrolysis of inorganic and organic derivatives of initial metals, in particular the sol-gel method [5,7], hydrothermal synthesis [1,12], a modified wet impregnation method [13], ultrasound-assisted co-precipitation method [3], Pechini process, and gel evaporation method [2] and others. However, the structure, composition and dispersion, and physical and physicochemical properties of the synthesized systems depend on the method of preparation thereof.…”

Evaluating the potential of CNT-supported Co catalyst used for gas pollution removal in the incineration flue gas

“…As we know, CNTs could be synthesized simply by chemical vapor deposition (CVD) at high temperature over Al 2 O 3 -supported catalysts (Colomer et al, 1999;Kukovecz et al, 2000;Ding et al, 2004;Dikonimos Makris et al, 2005). In the present study, we used various Al 2 O 3 catalysts (Cu, Co, Fe, and Ni) under different conditions to synthesize CNTs.…”