Resin‐Derived Hierarchical Porous Carbon Spheres with High Catalytic Performance in the Oxidative Dehydrogenation of Ethylbenzene

Abstract

Pre-shaped hierarchical porous carbon (HPC) spheres have been synthesized through a facile anion exchanged route. An industrial polymeric anion-exchange resin with a hierarchical pore structure was used as the carbon precursor. Its high porosity was conserved using an aluminate/silicate precursor forming a hard support to prevent the structural collapse during the carbonization process. Physicochemical bulk and surface properties of the obtained HPC spheres were characterized by X-ray diffraction, scanning and transmission electron microscopy, N(2) physisorption, and X-ray photoemission spectroscopy. Results obtained indicate that HPC keeps the abundant hierarchical porosity including meso- and macropores as well as the high surface area of the resin precursor. The as-synthesized HPC spheres were tested as a catalyst for oxidative dehydrogenation of ethylbenzene to styrene. The oxygen-rich catalyst surface formed under reaction conditions shows a high catalytic performance and stability, making HPC to a potential catalyst for this type of reaction.

Metal‐Free Carbonaceous Materials as Promising Heterogeneous Catalysts

“…But the styrene yield decreased from 40.3 to 32.3 % after only 400 min. Hierarchical porous carbon, with high surface area of 1520 m 2 g −1 synthesized through an anion‐exchange method, displayed a styrene selectivity of 75.0 % (598 K, oxygen/ethylbenzene=5:1),121 similar to that of microporous activated carbon (648 K, oxygen/ethylbenzene=5:1) 116. The high fraction of macropores and mesopores (0.76 cm 3 g −1 ) of hierarchical porous carbon resulted in an active and stable pre‐shaped catalyst for ODH of ethylbenzene.…”

Nanoengineering Carbon Spheres as Nanoreactors for Sustainable Energy Applications

“…Moreover, the second method to enhance the crosslinking is to coat the carbon precursor such as polymer with a layer of an aluminosilicate. For example, Xiao and co‐workers synthesized hierarchical porous carbon spheres via a facile anion exchange process with the assistance from aluminosilicate coating to prevent structural collapse . Another possible method is to use temperature programming with holding at relatively low temperature such as 200 °C for a certain time before reaching the final temperature and with a slow ramping rate.…”

“…Our group have also developed a facile method to prepare mesoporous nitrogen‐doped carbon nanospheres (Figure b,c), which have a microporous shell with a mesoporous interior, through a dual surfactant template method. These nanospheres exhibited excellent ORR performance due to their unique mesoporous structure and nitrogen doping …”

Modulating the microstructure and surface chemistry of carbocatalysts for oxidative and direct dehydrogenation: A review

“…The catalytic performance of carbon materials for the ODH reaction of hydrocarbons including light alkanes and ethylbenzene is significantly dependent on the morphology and size. In order to improve the catalytic performance of carbocatalysts, a large number of reports focused on tuning the shape, size and texture properties of the existing carbon materials through either post-treatment or the adjustment of synthesis process conditions [69,74,75,[92][93][94][95][96][97][98][99][100][101][102][103][104][105][106], as well as the design and synthesis of carbon materials with new morphologies [66,[107][108][109][110]. Moreover, although nanocarbons have shown promising performance in the ODH reaction, the fine powder nature of the carbocatalysts is highly detrimental to their use in fixed bed reactors.…”