Copper-cerium oxide catalysts prepared by the Pechini method for CO removal from hydrogen-containing mixtures

A series of copper-cerium oxide catalysts was prepared by the Pechini method, and their physicochemical and catalytic properties in CO oxidation in hydrogen-containing gas mixtures were studied. The method chosen for catalyst preparation yields finely dispersed copper and cerium oxides in the catalyst.     

Design of medium–temperature solid oxide fuel cells on porous supports of deformation strengthened Ni–Al alloy

An approach was developed towards design of medium-temperature solid-oxide fuel cells based on a deformation strengthened Ni-Al alloy. Methods of sintering were described that allowed obtaining layers of complex oxides with ionic and mixed conductivity and with regulated porosity in the range of 40–1%. Power density of a fuel cell on a metallic support reaches 500 mW/cm² already at 700°C when humid H₂ was used as fuel and air was used as an oxidant. Analysis of fuel cell cross-section after tests showed absence of fractures, flaking, and new phases with low conductivity, which proves good compatibility of all materials used in fuel cell design.     

Synthesis of nanosize Co-Rh systems and study of their properties

Precursor compounds [Co(NH₃)₆][Rh(NO₂)₆] and [Co(NH₃)₆][Co(NO₂)₆], solid solutions [Co(NH₃)₆] [Rh(NO₂)₆]_1−x [Co(NO₂)₆] _x , and solid solutions Na₃[Rh_1−x Co _x (NO₂)₆] were synthesized and studied by IR spectroscopy and elemental, X-ray phase, X-ray diffraction, and thermogravimetric analyses. X-ray phase analysis was employed to examine products of thermal decomposition of precursors in the atmospheres of hydrogen and helium. Catalysts with a Co-Rh active system, supported by ZrO₂, were prepared and tested in the reaction of steam conversion of ethanol.     

Reduction of nitrogen oxides in diesel exhaust: Prospects for use of synthesis gas

Already commercialized and some of the most promising technologies of nitrogen oxide reduction in automotive diesel exhaust are compared. The Boreskov Institute of Catalysis (Siberian Branch, Russian Academy of Sciences) is developing an advanced method for the selective catalytic reduction of NO _x with synthesis gas produced on board by the catalytic conversion of diesel fuel. The activity of the Ag/Al₂O₃ catalytic system in NO _x reduction by H₂ + CO admixtures is studied for both a model composition of the exhaust gas and under real diesel operation conditions.     

Performance of Single-Chamber Solid Oxide Fuel Cells Based on Ni and Ni–Cu Alloy Anodes and Fed with a Methane–Air Mixture

Kinetics and Catalysis - The electrochemical characteristics of Ni|YSZ|LSM and Ni–Cu|YSZ|LSM single-chamber solid oxide fuel cells fed with a methane–air mixture ([CH4]/[O2] molar ratio...     

Determination of electron affinity of carbonyl radicals by means of negative ion mass spectrometry

Appearance energies of [M-H](-) ions from carbonyl compounds R-CO-R' (R,R' = H, CH(3), NH(2), OH) have been measured by means of negative ion mass spectrometry in resonant electron capture mode. Values of electron affinity of the corresponding radicals, CH(2)&dbond;C(X)O, NH&dbond;C(X)O and O&dbond;C(X)O, have been determined. Copyright 1999 John Wiley & Sons, Ltd.     

Three-step macrokinetic model of butane and propane steam conversion to methane-rich gas

Low-temperature steam conversion (LTSC) of a methane-butane mixture (95% methane and 5% butane) into a methane-rich gas over an industrial Ni-based catalyst has been studied with the following reaction conditions: temperature 200–320°C, pressure 1 bar, gas hour space velocity 1200–3600 h^–1, and steam to carbon ratio 0.64. A three-step macrokinetic model has been suggested based on the kinetic parameters found. The model includes the following reactions: (1) irreversible steam reforming; (2) CO₂ methanation, which occurs in a quasi-equilibrium mode at temperatures above 260°C; (3) hydrogenolysis of propane and butane, which is essential at temperatures below 260°C. Steam reforming was shown to limit the overall reaction rate, whereas hydrogenolysis and CO₂ methanation determined the product distribution in low- and high-temperature regions, respectively. Temperature dependencies of the product distribution for the LTSC of a model ternary methane-propane-butane mixture (85% methane, 10% propane, and 5% butane) have been successfully simulated using the three-step model suggested.     

A Study of the Electrochemical Characteristics of Single-Chamber Solid Oxide Fuel Cells Based on Platinum and Strontium-Doped Lanthanum Manganite Electrodes and Fed with a Methane–Air Mixture

Kinetics and Catalysis - The properties of single-chamber solid oxide fuel cells (SC SOFCs) composed of an electrolyte based on yttria-stabilized zirconia (YSZ), a platinum anode, and a...     

The multi-functional aspect of scanning holographic microscopy: a review(Invited Paper)

Recent developments in scanning holographic microscopy that offer the prospects of new quantitative tools and imaging modalities in bio, micro, and nano sciences are reviewed. The versatility of the method is emphasized. Scanning holography can operate in an incoherent mode for fluorescence imaging, in a coherent mode for quantitative phase imaging, or in a tomographic mode for axial sectioning and rejection of the out-of-focus haze. Possible applications are illustrated with examples, and future prospects ...