Synthesis of Porous Fe₃C‐Based Composite Beads as Heterogeneous Oxidation Catalysts

Abstract

A series of multiscale cementite/iron/porous carbon (CIPC‐T) composites with extremely low nitrogen content and millimeter‐size spherical morphology were prepared by simple carbothermal pyrolysis of resin spheres exchanged with ferric oxalate anions. CIPC‐T materials are composed of highly disperse core–shell‐structured Fe3C/Fe@graphitic carbon (CI@GC) nanoparticles embedded in a porous amorphous carbon framework. A mechanism for the formation of the composites is proposed on the basis of the results of XRD, SEM, TEM, and thermogravimetric analysis. The Fe3C content can be easily controlled just by using different carbothermal temperatures. The CIPC‐T materials proved to be active as heterogeneous catalysts for oxidation of ethylbenzene to acetophenone and Fenton‐like oxidation of methylene blue. For the first time, the role of Fe3C in catalytic oxidation was confirmed. The spherical morphology of the composites and magnetic property facilitate separation of the catalyst from the reaction solution. More importantly, no leaching of iron active sites occurs during the reactions and the catalyst can be reused in continuous runs without obvious loss of activity. Such high stability of iron sites in the composites is ascribed to the protecting outer graphitic carbon shell of CI@GC.

Full use of factors promoting catalytic performance of chitosan supported manganese porphyrin

“…The independent variables coded at three level (− 1, 0, and + 1) and their change ranges were listed in Table 1. The total number of experiments for 17 listed in Table 2 were obtained according to a 3 3 Box-Behnken experimental design (BBD).…”

“…) on TON are concerned, the coefficient value of the quadratic parameter (X 3 2 ) was + 21.80 [Eq. (4)], showing a positive effect of X 3 2 on TON, displaying a greatest synergic effect (synergy), and having a greatest significant effect.…”

Highly Efficient Dynamic Degradation of Methylene Blue on Hierarchical Nitrogen/Cobalt‐Co‐Doped Carbonaceous Beads with Diffusion Promoting Nanostructures

“…Different valent cobalt and PMS would despoil (or lose) an electron, [43] and turned into the corresponding substances. Additionally, metal cobalt also can be oxidized into various valent of cobalt, as per eqn (15)(16)(17)(18). There is no doubt that it would induce the increasing in active ingredients.…”

“…However, even though those previously prepared catalysts have demonstrated respectably performance, there is still large room to further enhance efficiency. Modifying the interior nanostructures of materials is favorable for the unlimited accessibility between reactants and active sites . It was shown that the developed interior porosity and enlarged surface area play an important role in efficiency enhancement, considering that the diffusion pathway of the ions/molecules were a determining factor for the whole reaction process .…”

“…Modifying the interior nanostructures of materials is favorable for the unlimited accessibility between reactants and active sites. [15] It was shown that the developed interior porosity and enlarged surface area play an important role in efficiency enhancement, considering that the diffusion pathway of the ions/molecules were a determining factor for the whole reaction process. [16] For designing such kinds of high-performance catalytic composites, researchers found that the employing of hard-templating agents, e. g. calcium carbonate nanoparticles, can endow materials with fascinating nanostructured characteristics.…”