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Iron-incorporated ordered carbonaceous frameworks (OCFs) have been synthesized by the pyrolysis of iron porphyrin with ethynyl groups as polymerizable/carbonizable moieties at a temperature higher than 600 °C. The pyrolysis behavior is analyzed by thermogravimetry-differential thermal analysis-mass spectrometry, and the obtained carbon materials are characterized by X-ray diffraction, X-ray absorption fine structure, and high-angle annular dark-field scanning transmission electron microscopy. The introduction of ethynyl groups at the meta positions of the peripheral phenyl groups is essential for efficient cross-linking upon thermal polymerization. The thermally stable polymer thus obtained can be transformed into OCFs with high carbonization yield of 93 % at the subsequent carbonization. OCFs possess periodic structural regularity and porphyrin Fe-N4 coordination structure, and exhibit electrocatalysis for the conversion of CO2 into CO.

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.

Facile and efficient methods to prepare active electrodes for redox reactions of electrolyte ions are required to produce efficient and low-cost redox flow batteries (RFBs). Carbon-fiber electrodes are widely used in various types of RFBs and surface oxidation is commonly performed to enhance the redox reactions, although it is not necessarily efficient. Quite recently, a technique for nanoscale and uniform surface etching of the carbon fiber surface was developed and a significant enhancement of the negative electrode reaction of vanadium redox flow batteries was attained, although the enhancement was limited to the positive electrode reaction. In this study, we attempted to obtain an additional enhancement effect of metal-oxide nanoparticles without the need for further processing steps. A coating with carbonaceous thin films was obtained coating by sublimation, deposition, and pyrolysis of tin(II) phthalocyanine (SnPc) on a carbon fiber surface in a single heat-treatment step. The subsequent thermal oxidation concurrently achieved nanoscale surface etching and loading with SnO2 nanoparticles. The nanoscale-etched and SnO2-loaded surface was characterized by field-emission scanning electron microscopy (FESEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The activity for the vanadium ion redox reactions was evaluated by cyclic voltammetry (CV) to demonstrate the enhancement of both the positive and negative electrode reactions. A full cell test of the vanadium redox flow battery (VRFB) showed a significant decrease of the overpotential and a stable cycling performance. A facile and efficient technique based on the nanoscale processing of the carbon fiber surface was presented to substantially enhance the activity for the redox reactions in redox flow batteries.

Assembly of graphitized carbon nanowalls containing crystallites with the ideal interlayer distance was formed as a Voronoi cell structure of close-packed template nanoparticles. The assembly showed faster Li-ion intercalation and deintercalation than conventional graphite, a superhydrophobicity, which was retained even after thermal oxidation, and a high stability under electrochemical oxidative conditions.

Very fine Ni nanoparticles including subnanoclusters are dispersed in zeolite-templated carbon (ZTC), by thermal decomposition (573 K) of nickelocene pre-loaded on ZTC which functions as a high-surface area support. X-ray absorption fine structure reveals that the Ni species formed by the thermal decomposition is in a unique oxidized state. It is different from nickelocene, Ni metal, or any other inorganic Ni species. The unique Ni species can dissociatively adsorb H2, and enhance the following spillover even under ambient conditions. The spillover activity of the non-metallic Ni subnanoclusters is superior to that of Ni-metal nanoparticles and even comparable to that of Pt nanoparticles.

A metal-containing carbonaceous two-dimensional lattice was formed on a graphene plane by sublimation, deposition, and pyrolysis of Fe phthalocyanine (Pc). The formation and growth of the FePc-derived π-conjugated planar system were reflected by its orientation conversion from the perpendicular to horizontal mode and by the N K-edge X-ray absorption near-edge structure.

Activated carbons, BC-PANnp-ACs and BC-PANnp-KACs, have been synthesized from a composite (BC-PANnp) derived from bacterial cellulose (BC) and polyacrylonitrile nanoparticles (PANnp) by physical and chemical activation, respectively. Commercially available nata de coco has been used as the source of BC whereas PAN nanoparticles of ca. 100 nm have been synthesized in situ in the BC gel by emulsion polymerization which covers the nanofibers of BC. FE-SEM images confirm that hierarchical lamellar structure of BC is retained in the activated carbon frameworks. Detailed electrochemical studies carried out with the electrodes designed with the activated carbons reveal their good performance as electric double layer capacitors (EDLC) with fast response and high-speed charging and discharging. The activated carbons prepared by KOH activation have much higher specific surface area and exhibit better electrochemical properties compared to the carbon materials obtained by CO2 activation or the commercially available YP50F activated carbon derived from coconut shell. The three-dimensional network structure peculiar to BC reduces the grain boundary resistance between the carbonized PAN nanoparticles in these composites compared to PAN nanoparticles carbonized alone imparting good conductivity without the addition of a conductive agent.

Surface treatments are often applied to carbon materials to impart specific functions to the surface. Surface oxidation is a typical treatment to form oxygen-containing surface functional groups on carbon fiber electrodes of redox flow batteries in order to enhance the performance, which has attracted much attention as a large-scale electric energy storage system. At present, however, little attention has been paid to the effect of the edge plane exposure. In this study, fine etching of the graphitized carbon fiber surface was attained by coating the surface with a metal-containing carbonaceous thin film and thermal oxidation. The etching was caused by the catalysis of the metal species; the mechanism and the effect of the carbonaceous film were demonstrated by in situ X-ray absorption fine structure measurements. The finely etched surface possessed substantially enriched edge planes and an enhanced activity for the positive and negative electrode reactions of the vanadium redox flow battery. The flow cel...

Nitrogen-doped porous monolithic carbon (NDPMC) is obtained from biomass-derived activated carbon/polyacrylonitrile composite for the first time via a template-free thermally induced phase separation (TIPS) approach followed by KOH activation. The electrochemical results indicate that NDPMC possesses ultrahigh specific capacitance of 442 F g−1 at 1 A g−1, excellent rate capability with 81% retention rate from 1 to 100 A g−1 and outstanding cycling stability with 98% capacitance retention at 20 A g−1 after 5000 cycles. Furthermore, the evaluation of NDPMC on the practical symmetrical system also exhibits desired electrochemical performances. The novel composite carbon displays remarkable capacitance properties and the feasible, low-cost synthetic route demonstrates great potential for large-scale production of high-performance electrode materials for supercapacitors.

Despite recent advances in the carbonization of organic crystalline solids like metal-organic frameworks or supramolecular frameworks, it has been challenging to convert crystalline organic solids into ordered carbonaceous frameworks. Herein, we report a route to attaining such ordered frameworks via the carbonization of an organic crystal of a Ni-containing cyclic porphyrin dimer (Ni2-CPDPy). This dimer comprises two Ni–porphyrins linked by two butadiyne (diacetylene) moieties through phenyl groups. The Ni2-CPDPy crystal is thermally converted into a crystalline covalent-organic framework at 581 K and is further converted into ordered carbonaceous frameworks equipped with electrical conductivity by subsequent carbonization at 873–1073 K. In addition, the porphyrin’s Ni–N4 unit is also well retained and embedded in the final framework. The resulting ordered carbonaceous frameworks exhibit an intermediate structure, between organic-based frameworks and carbon materials, with advantageous electrocatalysis. This principle enables the chemical molecular-level structural design of three-dimensional carbonaceous frameworks., Carbon-based materials are promising alternatives to noble metal catalysts, but their structures are typically disordered and difficult to control. Here, the authors obtain ordered carbonaceous frameworks with advantageous electrocatalytic properties via the carbonization of nickel-containing porphyrin dimer networks.

N-doped porous monolithic carbons (PMC) have been developed from polyacrylonitrile (PAN) via a template-free thermally induced phase separation (TIPS) approach followed by an easy pyrolysis process. Three-dimensional (3D) PAN monolith (PM) was firstly fabricated as the starting material. The shape of the 3D PM was designed during the phase separation step, revealing that the product carbons had the potential advantages of desired porosity and controllable shape. Two typical activation methods were employed and compared to prepare PMC. KOH-activated PMC showed a larger surface area of 1600 m2 g−1 and higher nitrogen content of 5.6% in comparison to that being activated in a carbon dioxide atmosphere (CD-PMC). The electrochemical measurements revealed that PMC possessed a high capacitance of 270 F g−1 at 0.2 A g−1 and 195 F g−1 even at 100 A g−1, ultra-high rate capability with 72% capacitance retention from 0.2 to 100 A g−1 and outstanding cycling stability with 100% capacitance retention at 20 A g−1 after 5000 cycles. These results demonstrate that the present facile and efficient synthetic strategy for PMC from PAN can benefit the promotion of its application in energy storage devices and it is highly likely to be extended to other polymer sources.

Interest in chiral substances has mainly focused on the substances themselves, but not on the accompanying space, especially regarding the pore alignment. As a method to form both the chiral substance and the accompanying space, cylindrical self-assembly of uniform polystyrene nanoparticles with fructose is carried out in the presence of both carbon and sodium alginate, which is followed by heat treatment in an inert atmosphere. The carbonization generates fructose-derived honeycomb-like carbon walls with helically aligned nanopores left after the polystyrene decomposition. The diffuse reflectance circular dichroism measurements give peaks with opposite signs for the d- and l-fructose-derived cylindrical carbons. Circularly polarized light sensitivity in transient photoconductivity is confirmed apparently in the carbon-based helical structures. This sensitivity as well as straightforward formation of composites with another component to give helicity shows potential applications of the helically aligned pores.

Bifunctional catalysts for oxygen reduction and evolution reactions are essential components of zinc–air batteries (ZABs) for the air electrode. Carbonaceous materials have been investigated as these catalysts since the early stage of ZAB research. Recent studies have revealed promising carbonaceous materials with heteroatoms and transition metals doped into the surface or incorporated as nanoparticles, although the activity still needs improvement. In this study, the double coating of carbonaceous thin film containing Fe and N on a graphitic carbon fiber surface was performed via sublimation, deposition, and pyrolysis of iron phthalocyanine (FePc). In the first coating, the thin film and Fe nano-aggregates on the surface were generated, which were encapsulated in the carbonaceous shell to generate protrusions in the second coating. The presence of the protrusion enhanced the oxygen reduction activity. Such protrusion was also formed by the single coating with a sufficient FePc feed; however, the activity enhancement was limited. Contrarily, the double coating considerably enhanced the activity and surpassed that of Pt in the high potential region. In addition, the oxygen evolution reaction was improved by the FePc-derived thin film coating. The durability was confirmed by the stable cycling performance of ZAB with the double-coated electrode.

It has been found that carbonaceous materials containing a transition metal coordinated by 4 nitrogens in the square-planar configuration (metal–N4 site) on the surface possessed a catalytic activity for various electrochemical reactions related to energy conversion and storage; i.e., oxygen reduction, hydrogen evolution, and quite recently, the electrode reactions in vanadium redox flow batteries (VRFB). The catalyst for the VRFB positive electrode discharge reaction, i.e., the dioxovanadium ion reduction, was formed by coating the surface of cup-stack carbon nanotubes with a carbonaceous thin film with the Fe–N4 site generated by the sublimation, deposition, and pyrolysis of iron phthalocyanine. In this study, the influence of the physical properties of the catalyst on the electrochemical reactions was investigated to optimize the coating. With an increase in the coating, the specific surface area increased, whereas the pore size decreased. The surface Fe concentration was increased in spite of the Fe aggregation inside the carbon matrix. The catalytic activity enhancement was achieved due to the increase in the specific surface area and the surface Fe concentration, but was lowered due to the decrease in the pore size, which was disadvantageous for the penetration of the electrolyte and the mass transfer.

Bacterial cellulose (BC) gel is synthesized by static culture process at the interface between air and medium. The solvent-exchanged BC gel is incorporated into polyacrylonitrile (PAN) copolymer solution under heating at 90 °C and subsequent cooling gives bacterial cellulose-polyacrylonitrile composite (BC-PAN) monolith. The BC-PAN monolith is carbonized at 1000 °C with physical activation in the presence of CO2 to obtain the activated carbon monolith, BC-PAN-AC, with large surface area and high microporosity. Unique morphologies are observed for BC gel which is propagated to the BC-PAN monolith and restored in BC-PAN-AC. The BC nanofibers remain entwined throughout the porous skeleton of the PAN backbone and the entangled structure helps in retaining the continuity of the matrix of BC-PAN-AC and reduce the grain boundary impedance for electrical conduction. Cyclic voltammetry shows that these activated carbons are good electrode materials in electric double layer capacitors (EDLC) with capability of high-speed charging and discharging.

Boron and nitrogen co-doped ordered microporous carbons with high surface areas are obtained by using NaY zeolite as a hard template and an ionic liquid, 1-ethyl-3-methylimidazolium tetracyanoborate (EMIT), as a BN source. An acetylene-gas supply during a pyrolysis is effective to avoid the unfavourable reaction of zeolite and EMIT.

Carbon materials containing Fe coordinated by N atoms (Fe–N x moiety) embedded in the surface have been attracting much attention as noble-metal-free oxygen reduction catalysts for polymer electrolyte fuel cells. A carbonaceous thin film containing N-coordinated Fe and Co was formed from Fe and Co phthalocyanines on the basal plane of highly-oriented pyrolytic graphite to fundamentally investigate the effects of the addition of another kind of metal. An increase in the oxygen reduction current was observed for the carbonaceous thin film compared to those containing only either metal, suggesting the synergetic effect of their coexistence. [TANSO 2014 (No. 265) 165–168.]

Graphene layers with silica pillars which widen the interlayer distance and functionalize the space as micropores have been prepared as one of the new porous carbon materials. In this study, the silica-pillared graphene with Fe–N units as a catalytic active site for cathodic oxygen reduction was formed as a new type of carbonaceous noble-metal-free oxygen reduction catalysts with the ordered pore structure. The formation of the pillared carbon was performed by introducing silylating reagents as the pillar source and also as the nitrogen source of the units in the graphite oxide interlayer spaces, introducing the Fe ions, and heat treatment in vacuum at 500 °C. The X-ray diffraction (XRD) patterns showed the ordered layered structure. The X-ray absorption fine structure (XAFS) of the Fe- K edge showed that the unit was a square planar Fe–N 4 moiety. The catalytic activity for the O 2 reduction was demonstrated by measurements using rotating disk electrodes with the pillared carbon fixed on the surface and immersed in an oxygen-saturated acidic solution. The activity was enhanced by the combination of the nitrogen containing compound to the silylating reagent and using the nitrogen-rich silylating reagent.

The development of new methods for the formation of noble-metal-free fuel cell catalysts is currently important in order to provide active catalysts and to realize fuel cell advancements. We attempted the one-pot physical–chemical vapor deposition of iron phthalocyanine (FePc) on the surface of high-surface-area carbon particles as the substrate. This method enabled loading of FePc on the carbon material and concurrent heat treatment, resulting in the formation of carbon–carbon composite nanoparticles with a catalytic activity for the cathodic oxygen reduction, which functioned in a cathode in the polymer electrolyte fuel cell. The increasing temperature rate during the heat treatment, arranging the FePc–substrate configuration and simply adjusting their ratio controlled the amount of the loading and the thickness of the carbonaceous film, which was demonstrated by the transmission electron microscope images and the pore structure analysis. The catalytic activity was dependent on these parameters. The partial retention of the center structure of the FePc (Fe–Nx moiety) in the carbonaceous thin film was indicated by the Fe-K edge extended X-ray absorption fine structure. The results of this study also showed the possibility of coating various kinds of nanoparticles with functional carbonaceous thin films.

Various carbon materials with a characteristic morphology and pore structure have been produced using template methods in which a carbon-template composite is once formed and the characteristic features derived from the template are generated after the template removal. In this study, hemoglobin, which is a natural compound that could be abundantly and inexpensively obtained, was used as the carbon material source to produce a carbonaceous noble-metal-free fuel cell cathode catalyst. Magnesium oxide was used as the template concurrently generated with the hemoglobin carbonization from magnesium acetate mixed with hemoglobin as the starting material mixture to enable pore development for improving the activity of the carbonized hemoglobin for the cathodic oxygen reduction. After removal of the MgO template, the substantially developed pores were generated in the carbonized hemoglobin with an amorphous structure observed by total-electron-yield X-ray absorption. The extended X-ray absorption fine structure at the Fe-K edge indicated that Fe was coordinated with four nitrogen atoms (Fe-N(4) moiety) in the carbonized hemoglobin. The oxygen reduction activity of the carbonized hemoglobin evaluated using rotating disk electrodes was dependent on the pore structure. The highly developed pores led to an improved activity.

A carbonaceous thin film containing Fe and N was formed on a basal plane of highly oriented pyrolytic graphite (HOPG) from iron phthalocyanine (FePc). Hybrid physical–chemical vapor deposition (HPCVD) in a single vessel through a simple heat treatment at atmospheric pressure enabled the formation and was found to be a facile and versatile method. The catalytic activity of the thin film for O2 reduction was as high as dispersed Pt on a flat glassy carbon (GC) surface in an acidic electrolyte, implying high potential of the carbonaceous materials as well as the formation method. Keywords: Hybrid physical–chemical vapor deposition, Carbonaceous thin film, Oxygen reduction, Fuel cell, Cathode catalyst

In contrast to conventional solid materials used as precursors for carbon materials, which are typically organic polymers and macromolecules, a solid of relatively small organic molecules mixed with metal salts was directly used to form a functional carbon material. Heat treatment of a mixture of 1,4-diamino-2,3-dicyano-9,10-anthraquinone, Fe gluconate, and Mg acetate produced a highly porous carbon material functioning as a noble-metal-free fuel cell cathode catalyst with Fe coordinated by N atoms embedded in the pore surface as the active sites. Its function was confirmed by electricity generation in a polymer electrolyte fuel cell formed using it in the cathode. The high durability of the fuel cell was demonstrated by its continuous operation. This study showed the possibility of forming a wide variety of finely designed functional carbon materials by the proper selection of small organic molecules and metals.

Enhancement of oxygen reduction at a catalyst layer formed from a Pt-loaded activated carbon (Pt/AC) with adsorbed CF3SO3H compared to that from Pt/carbon black (Pt/C) was recently found using rotating disk electrodes (RDE). In this study, we verified the enhancement at fuel cells formed by using Pt/AC in the cathode catalyst layer. At the relative humidity of 100%, the PEFC formed from Pt/AC showed better performance than that formed from the Pt/C in the cathodes. The adsorption of CF3SO3H onto Pt/AC further improved the performance. This tendency was in agreement with the results of the RDE measurements. At the relative humidity of 25%, although the hydrophilicity of the catalysts affected the kinetics of oxygen reduction and the cell resistance, the same tendency of the PEFC performance was observed. The results suggest the usefulness of Pt-loaded activated carbon with CF3SO3H for improvement of PEFC performance.

Raw materials for producing polymer electrolyte fuel cells should be inexpensive and abundant in their resource in order to widely substitute this new energy system for conventional ones. In this study, a catalyst for the cathodic oxygen reduction was formed from hemoglobin, a large amount of which would be always available. The heat treatment in an inert atmosphere around 800 °C produced a carbonized material with highly developed nanospaces. The specific surface area reached 1005 m2 g-1 at the optimized carbonization conditions. The fundamental electrochemical properties were evaluated using rotating disk electrodes, forming a catalyst layer from the carbonized material with the polymer electrolyte on the electrode surface and immersing the layer in oxygen-saturated perchloric acid. We found that the carbonized materials were active toward oxygen reduction and the activity increased with the nanospace development, essential for exposing the active sites on the pore surface. The oxygen reduction behavior...

The amount of platinum in the catalyst for the electrodes of polymer electrolyte fuel cells must be minimized to widely substitute this new energy system for conventional ones. In this study, a platinum-free catalyst for the cathodic oxygen reduction was formed from a natural organic compound, catalase. We carbonized catalase to produce a catalyst active in the superacidic atmosphere of the polymer electrolyte. Nitrogen adsorption onto the carbonized material revealed that the material had highly developed internal nanospaces, which were essential for exposing active sites to oxygen reduction on the pore surface. The carbonized material was also characterized by X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, and Mossbauer spectroscopy. The activity for oxygen reduction was evaluated using rotating disk electrodes, forming a catalyst layer from the carbonized material and the polymer electrolyte on the electrode surface and immersing the layer in oxygen-saturated per...

Attention has now been paid to platinum-free catalysts aiming at widespread use of polymer electrolyte fuel cells (PEFCs) after their realization as a power source of electric vehicles and on-site cogeneration systems. In this review, we describe cathode catalysts consisting of iron bound to surfaces of carbon materials through nitrogen atoms, denoted here as FeNx-C catalysts, which are formed by heat-treatment. Methods for FeNx-C catalyst formation are classified according to iron-containing compounds and nitrogen sources of the precursors. Difference in the catalysis from conventional Pt-based catalysts, the structure of the active site, the mechanism of oxygen reduction, and long-term durability at the catalysts are discussed. Especially, we mention that the activity of the FeNx-C catalysts per metal weight is comparable to that of the Pt-based catalysts; a FeNx-C catalyst electrode whose performance exceeds those of Pt-based electrodes has been already reported, and that stable performance of FeNx-C catalysts has also been reported. It is reasonable to conclude that the FeN, -C catalysts have the potential to be applied to the cathode of the PEFC. Although the anode still needs the Pt-based catalysts, using FeNx-C catalysts could lead to significant reduction of the total amount of Pt used in the PEFC.

One of the obstacles to widespread use of polymer electrolyte fuel cells is the limitation of Pt reserves. In the present study, a catalyst for the cathode was formed from red blood cells, a large amount of which are discarded as waste at present. The heat-treatment in flowing argon produced a carbonized material with highly-developed micropores. The specific surface area reached 883m2g-1 at the optimized carbonization conditions. Catalysis at the carbonized material for cathodic oxygen reduction was investigated using rotating disk electrodes (RDE), forming a layer from the material and the polymer electrolyte on the electrode surface and immersing the layer in oxygen-saturated perchloric acid. The carbonized materials showed the catalytic activity toward oxygen reduction and the activity increased with an increase in the micropore development, which might increase the number of active sites exposed to the pore surface and efficiency of the each sites. A fuel cell was formed by applying the most active carbonized material in the RDE measurements to the cathode. Although the performance was inferior to a conventional fuel cell using a Pt catalyst, the current generation at the fuel cell using the carbonized red cell was confirmed.

Improvement of the polymer electrolyte fuel cell (PEFC) requires development of highly active electrodes of low cost to facilitate its widespread use. In the present study, the possibility of applying conventional activated carbon particles loaded with Pt to the electrode catalyst layer was tested because the particles were promising in dispersion of Pt and preparation cost. The catalyst layer was formed from the particles and Nafion® and was supported as a thin film on a rotating glassy carbon disk electrode (GC RDE). Activity for oxygen reduction was evaluated by the hydrodynamic voltammetry in perchloric acid to give a current free of the influence of mass transfer in the solution. Compared with a conventional catalyst layer formed from carbon black loaded with Pt, the new catalyst layer exhibited a significant, approximately 6-fold increase in current in the high potential region corresponding to a 100 mV increase in electrode potential. Activity, however, was retarded in the low potential region. This disadvantage was overcome by mixing a conductive agent into the layer and covering it with another layer containing carbon black loaded with Pt. This double catalyst layer exhibited increased activity across all potential regions, indicating the availability of the activated carbon in the electrodes.

Carbon supports of electrocatalysts have recently attracted much attention for improving the performance of polymer electrolyte fuel cells (PEFCs). In this study, the PEFCs were formed using activated carbon loaded with platinum of various pore structures in the cathode catalyst layer. The performance of the PEFC at the relative humidity of 100% was dependent on the specific surface area and the mean pore diameter. The behavior was correlated with the results obtained using rotating disk electrodes in a previous study. The PEFC performance was also examined in a low-humidity condition and found to be also dependent on the pore structure.

Highly porous N-doped activated carbon monoliths (ACMs) are fabricated by carbonization and physical activation of mesoporous polyacrylonitrile (PAN) monoliths in the presence of CO(2). The monoliths exhibit exceptionally high CO(2) uptake; 5.14 mmol g(-1) at ambient pressure and temperature and 11.51 mmol g(-1) at ambient pressure and 273 K.

Nine non-noble-metal catalysts (NNMCs) from five different laboratories were investigated for the catalysis of O(2) electroreduction in an acidic medium. The catalyst precursors were synthesized by wet impregnation, planetary ball milling, a foaming-agent technique, or a templating method. All catalyst precursors were subjected to one or more heat treatments at 700-1050 degrees C in an inert or reactive atmosphere. These catalysts underwent an identical set of electrochemical characterizations, including rotating-disk-electrode and polymer-electrolyte membrane fuel cell (PEMFC) tests and voltammetry under N(2). Ex situ characterization was comprised of X-ray photoelectron spectroscopy, neutron activation analysis, scanning electron microscopy, and N(2) adsorption and its analysis with an advanced model for carbonaceous powders. In PEMFC, several NNMCs display mass activities of 10-20 A g(-1) at 0.8 V versus a reversible hydrogen electrode, and one shows 80 A g(-1). The latter value corresponds to a volumetric activity of 19 A cm(-3) under reference conditions and represents one-seventh of the target defined by the U.S. Department of Energy for 2010 (130 A cm(-3)). The activity of all NNMCs is mainly governed by the microporous surface area, and active sites seem to be hosted in pore sizes of 5-15 A. The nitrogen and metal (iron or cobalt) seem to be present in sufficient amounts in the NNMCs and do not limit activity. The paper discusses probable directions for synthesizing more active NNMCs. This could be achieved through multiple pyrolysis steps, ball-milling steps, and control of the powder morphology by the addition of foaming agents and/or sulfur.

Saw-dust of Japanese cypress, which was often used as a raw material of activated carbon, impregnated with an aqueous solution of halide or organic acid salt was carbonized and the porosities of the carbonized samples were measured. When saw-dust impregnated with potassium or sodium iodide or bromide was carbonized at 800°C, chemical activation occurred and the carbonized sample had a larger specific surface area than one prepared by normal carbonization without using inorganic compounds. However, no chemical activation was found in the case of magnesium halides and other metal chlorides. In experiments using acetates, potassium caused stronger chemical activation than sodium or magnesium. It was also found that chemical activation did not occur in carbonization at 600°C and that the chemical activation occurred at a higher carbonization temperature than the melting point of the inorganic compound used. It is therefore believed that the reactivity of the inorganic compound, such as its corrosion of the carbonaceous solid, is intensified by using a higher carbonization temperature than its melting point in order to promote the chemical activation. [TANSO 2014 (No. 261), 8–13.]

Mesoporous polyacrylonitrile (PAN) monolith has been fabricated by a template-free approach using the unique affinity of PAN towards a water/dimethyl sulfoxide (DMSO) mixture. A newly developed Thermally Induced Phase Separation Technique (TIPS) has been used to obtain the polymer monoliths and their microstructures have been controlled by optimizing the concentration and cooling temperature.

A carbon-based noble-metal-free O(2) reduction catalyst for a polymer electrolyte fuel cell (PEFC) cathode was produced from commonplace, safe and inexpensive compounds (glucose, adenine, Fe gluconate) and the catalyst structure was controlled between a graphene-layered structure and a highly porous amorphous structure for the activity enhancement, which led to the power density of the highest level among the noble-metal-free cathode type PEFCs.