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Ordered carbonaceous frameworks (OCFs) are a new class of carbon materials with a three-dimensional ordered structure synthesized by simple carbonization of metalloporphyrin crystals with polymerizable moieties. Carbonization via solid-state polymerization results in the formation of graphene-based ordered frameworks in which regularly aligned single-atomic metals are embedded. These unique structural features afford molecular-level designability like organic-based frameworks together with high electrical conductivity, thermal/chemical stability, and mechanical flexibility, towards a variety of applications including electrocatalysis and force-driven phase transition. This feature article summarizes the synthetic strategies and characteristics of OCFs in comparison with conventional organic-based frameworks and porous carbons, to discuss the potential applications and further development of the OCF family. [ABSTRACT FROM AUTHOR]

Force-responsive ordered carbonaceous frameworks (OCFs) are synthesized for the first time. Carbonization of Ni porphyrin monomers having eight polymerizable ethynyl groups yields OCFs with atomically dispersed divalent Ni species and developed micropores. The highest specific surface area (673 m2 g−1) among the OCFs has been achieved. The OCFs thus synthesized comprise non-stacked graphene sheets, affording a unique mechanical flexibility that enables force-driven reversible phase transition. [ABSTRACT FROM AUTHOR]

Carbon materials with controlled pore sizes at the nanometer level have been obtained by template methods, chemical vapor desorption, and extraction of metals from carbides. However, to produce porous carbons with controlled pore sizes at the Ångstrom-level, syntheses that are simple, versatile, and reproducible are desired. Here, we report a synthetic method to prepare porous carbon materials with pore sizes that can be precisely controlled at the Ångstrom-level. Heating first induces thermal polymerization of selected three-dimensional aromatic molecules as the carbon sources, further heating results in extremely high carbonization yields (>86%). The porous carbon obtained from a tetrabiphenylmethane structure has a larger pore size (4.40 Å) than those from a spirobifluorene (4.07 Å) or a tetraphenylmethane precursor (4.05 Å). The porous carbon obtained from tetraphenylmethane is applied as an anode material for sodium-ion battery. Porous carbon materials are used widely in catalysis, electrochemistry, or as sorbents, but pore size control continues to be a challenge in their syntheses. Here the authors show that the 3D molecular structure of the carbon sources allows to control the pore size of the resulting carbon materials at the Ångstrom-level. [ABSTRACT FROM AUTHOR]

Porous carbon material with a foam-like microstructure has been synthesized by direct carbonization of porous coordination polymer (PCP). In situ generation of foaming agents by chemical reactions of ligands in PCP during carbonization provides a simple way to create lightweight carbon material with a foam-like microstructure. Among several substituents investigated, the nitro group has been shown to be the key to obtain the unique foam-like microstructure, which is due to the fast kinetics of gas evolution during carbonization. Foam-like microstructural carbon materials showed higher pore volume and specific capacitance compared to a microporous carbon. [ABSTRACT FROM AUTHOR]

We report a new synthesis method of fibrous carbon material with pores sizes that are precisely controlled at the Ångstrom level, by carbonization of two dimensional (2D) porous sheets of pillar[6]arenes. The 2D porous sheets were prepared by 2D supramolecular polymerization induced by oxidation of hydroquinone units of pillar[6]arenes. Owing to the hexagonal structure of pillar[6]arene, the assembly induced by 2D supramolecular polymerization gave hexagonal 2D porous sheets, and the highly ordered structure of the 2D porous sheets formed regular fibrous structures. Then, carbonization of the 2D porous sheets afforded fibrous carbon materials with micropores. The micropore size of the fibrous porous carbon prepared from pillar[6]arene was the same size as that of the starting material pillar[6]arene assembly. [ABSTRACT FROM AUTHOR]

Abstract: The entire pore surface of FSM-16 type mesoporous silica was uniformly coated with a thin carbon layer by carbonizing pre-doped organic-alcohol molecules onto the pore surface. The thickness of the carbon layer was estimated to be extremely thin, i.e., it corresponds to only 1–2 graphene layers. Even after the carbon-coating, FSM-16 preserves its intrinsic ordered pore structure (hexagonal array of cylindrical pores) and still possesses high surface area of 530m2 g−1, but its pore nature was completely converted into a hydrophobic one, which was revealed from a very small amount of water–vapor adsorption. We characterized the electrochemical properties of the carbon-coated FSM-16 together with the carbon-coated SBA-15 synthesized by using the same coating method. Both of them exhibited electric double-layer capacitance in 1M H2SO4 and 1M NaCl, and the values of the capacitance per surface area are comparable to those of conventional activated carbons. We can thus conclude that the present carbon-coating changes the nature of mesoporous silicas from an insulator to an electrical conductor with their ordered pore structures unchanged, and the carbon-coated mesoporous silicas can be used as electrode materials with uniform pores. [Copyright &y& Elsevier]

Ordered mesoporous carbon CMK-1 was prepared via carbonization at a relatively low temperature (the first step) followed by partial graphitization (the second step of carbonization at higher temperature) inside the ordered mesopores of cobalt-loaded mesoporous silica MCM-48 using polyacrylonitrile (PAN) as a carbon/nitrogen source. This first step of the carbonization is called "infusibilization", and the resultant material is denoted as PAN inf. In an advanced temperature-programmed desorption analysis of the PAN inf /MCM-48 composite, the temperature of the observed HCN signal indicated that carbonization was reduced from 550 to 450 °C by a Co catalyst. The amount of typical N 2 formation associated with the selective removal of pyridinic N species, resulting in the graphitic surface formation, also increased at a relatively high temperature (approximately 1000 °C) with the aid of the Co catalyst. The CMK-1 prepared through cobalt-catalyzed carbonization exhibited a higher electric double-layer capacitance with an Et 4 N+BF 4 –/propylene carbonate electrolyte, and higher electrical conductivity than CMK-1 prepared without a catalyst. This also implied the progress of graphitization within the carbonaceous wall. These results suggest that the edge planes of the graphitic domains in CMK-1 are predominantly exposed on the surfaces of the carbonaceous walls, resulting in an increase in the number of adsorptive sites for the electrolyte during capacitance measurements. [Display omitted] • CMK-1 obtained from polyacrylonitrile via cobalt-catalyzed carbonization showed a higher electric double-layer capacitance. • The advanced TPD and XPS analyses revealed the selective removal of pyridinic-N species during the carbonization from PAN. • Cobalt catalyst enhances the selective removal of pyridinic-N at 1000 °C. [ABSTRACT FROM AUTHOR]

Abstract: A new enzymatic process for production of l-theanine was presented using glutaminase combined with immobilization technique on carbon-coated mesoporous silica (carbon/SBA-15). For the attempt to enhance the durability against high pH conditions, the pore surface of mesoporous silica SBA-15 was coated with a thin layer of carbon. Carbon coating was done by addition of 2,3-dihydroxynaphthalene (DN) on the pore surface, followed by a dehydration reaction between surface silanol groups in SBA-15 and hydroxyl groups of DN molecules, and further carbonization of DN. A glutaminase was confined in nanospace (about 5nm) of carbon/SBA-15. The resulting product, glutaminase/carbon/SBA-15, successfully catalyzed the reaction for production of l-theanine under high pH conditions. [Copyright &y& Elsevier]