Nanocomposite electrode materials for low temperature solid oxide fuel cells using the ceria-carbonate composite electrolytes

Low temperature solid oxide fuel cell (LTSOFC, 300–600 °C) is one of the hot areas in recent fuel cell developments. In order to develop high performance LTSOFCs, compatible electrodes are highly demanded. We used NANOCOFC (nanocomposites for advanced fuel cell technology) approach to develop nanocomposite electrodes based on metal oxides Ni–Cu–Zn-oxide and samarium doped ceria (SDC). It was found that the materials consist of individual metal oxide and SDC phase, indicating the material as a composite with a homogenous distribution for all constituent components. Highly homogenous distribution of the particles enhanced the catalyst function for electrode applications in LTSOFC devices. We constructed the devices using the SDC-carbonate nanocomposite (NSDC) as the electrolyte and above as prepared composite as electrodes in a symmetrical configuration. We found that the prepared composite electrodes had good catalytic function for both H₂ and O₂, to prove its anode and cathode functions. Based on the material properties, the LTSOFC devices have reached a power output more than 730 mW cm⁻² at 550 °C.     

Relationship between oxidation states of copper supported on alumina and activities for catalytic combustion of NH3

The relationship between the oxidation state of Cu supported on an alumina catalyst (Cu/Al₂O₃) and the activity for combustion of NH₃ was investigated. Combustion of NH₃ on the catalyst treated in hydrogen at 800°C occurred at lower temperature than on the catalyst treated in air. It was also much better than Pt and Rh catalysts for the conversion of NH₃ to N₂. Characteristics of the catalyst were investigated by XRD, XPS, and the N₂O pulse injection method to understand the reason of its high catalytic activity. The reason of the high activity of the catalyst treated in hydrogen at the high temperature was attributed to the lower oxidation state of Cu in the catalyst. This revised version was published online in July 2006 with corrections to the Cover Date.     

Synthesis of large pore-size and large pore-volume aluminas by glycothermal treatment of aluminium alkoxide and subsequent calcination

Aluminas were prepared by calcination of the products obtained by glycothermal treatment of aluminium alkoxides, and their pore structures investigated by means of the nitrogen adsorption technique and mercury porosimetry. The product had a honeycomb-like texture which developed well with increasing crystallite size of the product. The crystallite size of the product was in turn controlled by the glycol used, and increased in the following order (carbon number of glycol): 2 < 3 < 6 4. The honeycomb-like texture was preserved even after calcination. Because of the well-developed honeycomb-like texture, the alumina derived from the product obtained by the treatment of aluminium isopropoxide in 1,4-butanediol had quite large pore diameters (70 and 700 nm) and a large pore volume (2.4cm³g^–1) with a sufficient surface area (184 m²g^–1).     

Pervaporation characteristics of methyl methacrylate–methacrylic acid copolymer membranes ionically crosslinked with metal ions for a benzene/cyclohexane mixture

Methyl methacrylate–methacrylic acid copolymer (MMA–MAA) membranes ionically crosslinked with Fe³⁺ and Co²⁺ ions (MMA–MAA–Fe³⁺ and –Co²⁺) were prepared, and characteristics of permeation and separation for a benzene/cyclohexane mixture of 50 wt % benzene through these membranes in pervaporation (PV) were studied. Although the introduction of the metal ions to the MMA–MAA membrane enhanced both benzene permselectivity and permeability for a benzene/cyclohexane mixture, the PV characteristics between the MMA–MAA–Fe³⁺ and –Co²⁺ membranes were significantly different. The difference in the PV characteristics between these membranes was strongly governed by the difference of these membrane structures based on the glass transition temperature, contact angle to methylene iodide, degree of swelling, and mixture composition absorbed in the membrane, and so on. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 233–241, 1999     

FI Catalysts: A New Family of High Performance Catalysts for Olefin Polymerization

This paper reviews a new family of olefin polymerization catalysts. The catalysts, named FI catalysts, are based on non‐symmetrical phenoxyimine chelate ligands combined with group 4 transition metals and were developed using “ligand‐oriented catalyst design”. FI catalysts display very high ethylene polymerization activities under mild conditions. The highest activity exhibited by a zirconium FI catalyst reached an astonishing catalyst turnover frequency (TOF) of 64,900 s ^–1 atm ^–1, which is two orders of magnitude greater than that seen with Cp₂ZrCl₂ under the same conditions. In addition, titanium FI catalysts with fluorinated ligands promote exceptionally high‐speed, living ethylene polymerization and can produce monodisperse high molecular weight polyethylenes (M_w/M_n<1.2, max. M_n>400,000) at 50 °C. The maximum TOF, 24,500 min ^–1 atm ^–1, is three orders of magnitude greater than those for known living ethylene polymerization catalysts. Moreover, the fluorinated FI catalysts promote stereospecific room‐temperature living polymerization of propylene to provide highly syndiotactic monodisperse polypropylene (max. [rr] 98%). The versatility of the FI catalysts allows for the creation of new polymers which are difficult or impossible to prepare using group 4 metallocene catalysts. For example, it is possible to prepare low molecular weight (M_v∼10³) polyethylene or poly(ethylene‐co‐propylene) with olefinic end groups, ultra‐high molecular weight polyethylene or poly(ethylene‐co‐propylene), high molecular weight poly(1‐hexene) with atactic structures including frequent regioerrors, monodisperse poly(ethylene‐co‐propylene) with various propylene contents, and a number of polyolefin block copolymers [e.g., polyethylene‐b‐poly(ethylene‐co‐propylene), syndiotactic polypropylene‐b‐poly(ethylene‐co‐propylene), polyethylene‐b‐poly(ethylene‐co‐propylene)‐b‐syndiotactic polypropylene]. These unique polymers are anticipated to possess novel material properties and uses.     

Complete oxidation of active carbon at low temperatures by composite catalysts

The reaction between oxygen and active carbon was studied at 500°C. Various composite catalysts having an iron-group metal as the main component were supported on active carbon. The synergistic effect of the oxidation activity was widely observed in the composite metal-metal oxide catalyst/carbon system. Several active carbons were studied in this catalyzed oxidation and the oxidation rate decreased with decreasing surface area of carbon materials. The rate-determining step of this reaction was considered to be the surface-diffusion rate of oxygen. Enhancement of oxygen transmission by active composite catalysts resulted in promotion of the reaction.     

Fast algorithm for computing color gamuts

A fast and accurate algorithm for computing color gamuts has been developed. In the form presented here for illustration, color gamuts are computed from the dye amounts of subtractive color mixtures. Based on the one-to-one correspondence between dye amount space and color space, the simple four-step algorithm performs a boundary search in dye amount space and a map over to color space. Application to block dyes and commercial reversal film dyes on a desktop computer demonstrates the algorithm's validity, accuracy, applicability, and exceptional speed. © 1993 John Wiley & Sons, Inc.     

Novel strengthening method of closed-cell aluminum foams through surface treatment by resin

Aluminum foams are focused on as a lightweight structural material because of their excellent energy absorbing capacity. However, compressive strength of aluminum foams is much lower than that of dense aluminum. This is due to local buckling of the inhomogeneous cell structure. The authors carried out infiltration of open surface pores with polyester resin because buckling starts at the open surface pores. Compressive tests using commercial aluminum foams show significant increases in compressive strength and absorbed energy. Since the density of resin is not high, the specific compressive strength and specific absorbed energy are also increased.