Nanostructured amorphous metals, alloys, and metal oxides as new catalysts for oxidation

Abstract

The oxidation of cyclohexane with molecular oxygen in the presence of isobutyraldehyde catalyzed by nanostructured iron and cobalt oxides and iron oxide supported on titania has been studied. Nanostructured cobalt oxide on MCM-41 is found to be efficient for catalytic aerobic epoxidation of olefins.

Catalytic oxidation of cyclohexane to cyclohexanol and cyclohexanone over Co3O4 nanocrystals with molecular oxygen

“…The properties of these materials mainly depend on their shape, size, and structure, which are strongly determined by the synthetic processes. Nanostructured catalysts, such as Fe 2 O 3 , Co 3 O 4 , and mixed Fe-Co oxide, have been employed in the cyclohexane oxidation [13][14][15]. Unfortunately, these catalysts are unstable during the reaction.…”

“…Unfortunately, these catalysts are unstable during the reaction. For example, employing Fe 2 O 3 nanoparticles as catalyst in cyclohexane oxidation, the conversion in the second run was decreased to about 70% of that in the first run [15]. The poor recyclability may attribute to the fact that the particles are amorphous and thus easy to leach into solution during reaction [15].…”

Nanobiotechnology for the production of biofuels from spent tea

“…Gates (2000) and others have employed molecular nano particles in catalysis. Cobalt nano particle catalysts may be influenced by their size and structure and by other additional components such as Si, Ni and Mg. For example, Co or Co oxide nanostructures are known to be effective catalysts (Yang et al, 2001;Kesavan et al, 2001;Son et al, 2002). Cobalt nano particles, in particular being cheap, need mild reaction conditions for high yields of products in short reaction times as compared to the traditional catalysts.…”

The Synthesis and Properties of High Surface Area Fe2O3Materials

“…Nanostructured iron oxides have found widespread interests in recent years [1][2][3][4]. Iron oxides and iron-based materials reveal often unique physical, optical, magnetic and catalytic properties.…”

“…These relatively cheap and nontoxic materials have many high-technology potential applications. They can be used for example for enhanced storage media [5,6], in biosensing, as contrast agents in magnetic resonance imaging [7] or drug and gene delivery [8], as ferrofluids [9] or catalysts [10]. The coercivity, saturation magnetization values of nanostructured iron oxides are strongly related to the size and magnetic anisotropy of the particles [11,12].…”