Development of Microporosity in Mesoporous Carbons

Abstract

Monolithic carbons with uniform and spherical mesopores can be easily obtained by filling the pores of colloidal silica monoliths with carbon precursors followed by carbonization and silica dissolution. In this study three different phenolic resin blends: resorcinol and crotonaldehyde (MC-RC), phenol and paraformaldehyde (MC-PP), and resorcinol and furfural (MC-RF) were used as carbon precursors. Subsequent heating and carbonization of the resulting silica-phenolic resin nanocomposites followed by silica dissolution afforded monolithic carbons with spherical mesopores matching the size of the silica colloids used. Development of microporosity in these carbons was achieved by post-synthesis KOH activation. This study shows that the combination of colloidal templating with post-synthesis activation affords monolithic micro-mesoporous carbons with large specific surface area and welldeveloped accessible porosity for adsorption, catalysis, environmental and energy-related applications.

Influence of carbon pore size on the discharge capacity of Li–O2batteries

“…52 Inverse opal carbon (IOC) was synthesized using assembled silica nanospheres as templates. 53 Briey, furfural and resorcinol were inltrated into a dried silica template (ST-OL, Nissan Chemical Industries, Ltd.), followed by a carbonization process at 1400 C over 2 h. The silica template was then removed by HF (46%) at room temperature over 12 h. Graphene oxide was prepared via a modied Hummers method, 54 and puried via a dialysis process over 1 week and freeze-dried. The reduction reaction was carried out at 1000 C under a 5% H 2 /Ar atmosphere for 1 h. The reduced product, reduced graphene oxide (rGO), was harvested as loosely packed powder with a dark color and used in the Li-O 2 battery test.…”

Multiscale adsorption and transport in hierarchical porous materials

“…Therefore, in addition to the typical length scale corresponding to the pore size, the grain or film size introduces a second characteristic length scale. 9,10 Moreover, to overcome limited mass transfer and poor access to the active sites in such microporous (o2 nm) or mesoporous (2-50 nm) materials, important efforts are devoted to design hierarchical materials which combine different porosity scales 11,12 such as mesoporous/microporous zeolites, 13,14 hierarchical porous silica [15][16][17] or carbon, 18 hierarchical mesoporous films, 19 particles supported in porous solids, 20,21 etc. These multiscale porous solids, which possess a large specific surface area of active sites together with large pores ensuring high permeability, have been shown to lead to enhanced properties towards different applications especially in catalysis and chromatography.…”

Hierarchical ordered mesoporous carbon from phloroglucinol-glyoxal and its application in capacitive deionization of brackish water

“…The mesoporous materials produced can then be further activated to introduce micropores and increase the surface area and pore volume. 19,20 Activated carbon powders, however, have the increased limitation of polymeric binders that are needed to hold the particulate together in a sheet-like formulation for affixing to current collectors. 21 Poor binder choice results in pore blockage or restrictions, thus reducing the ion capacity of the materials.…”