A ceramic fuel cell in an all solid-state energy conversion device that produces electricity by electrochemically combining fuel and oxidant gases across an ionic conducting oxide. Current ceramic fuel cells use an oxygen-ion conductor or a proton conductor as the electrolyte and operate at high temperatures (>600°C). Ceramic fuel cells, commonly referred to as solid-oxide fuel cells (SOFCs), are presently under development for a variety of power generation applications. This paper reviews the science and technology of ceramic fuel cells and discusses the critical issues posed by the development of this type of fuel cell. The emphasis is given to the discussion of component materials (especially, ZrO2 electrolyte, nickel/ZrO2 cermet anode, LaMnO3 cathode, and LaCrO3 interconnect), gas reactions at the electrodes, stack designs, and processing techniques used in the fabrication of required ceramic structures.

Ceramic Fuel Cells

A ZnO buffer layer having an electric conductivity of 1×10−9 S/cm or lower or alternatively a ZnO buffer layer having a diffraction peak of a crystal face other than (002) and (004) in X-ray diffraction is formed on a substrate by sputtering. A ZnO semiconductor layer is formed on the ZnO buffer layer. The ZnO semiconductor layer is formed under the condition that the flow rate ratio of an oxygen gas in a sputtering gas is lower than that in the formation of the ZnO buffer layer.

Method for forming ZnO film, method for forming ZnO semiconductor layer, method for fabricating semiconductor device, and semiconductor device

On etudie le depot chimique en phase vapeur et la croissance cristalline de revetement de diamant

/pdf/diamond-ceramic-coating-of-the-future-31m184yw0t.pdf

Diamond—Ceramic Coating of the Future

Durability of nanosized oxygen-barrier coatings on polymers

Thermal-catalytic gas processing is integral to many current industrial processes. Ever-increasing demands on conversion and energy efficiencies are a strong driving force for the development of alternative approaches. Similarly, synthesis of several functional materials (such as nanowires and nanotubes) demands special processing conditions. Plasma catalysis provides such an alternative, where the catalytic process is complemented by the use of plasmas that activate the source gas. This combination is often observed to result in a synergy between plasma and catalyst. This Review introduces the current state-of-the-art in plasma catalysis, including numerous examples where plasma catalysis has demonstrated its benefits or shows future potential, including CO2 conversion, hydrocarbon reforming, synthesis of nanomaterials, ammonia production, and abatement of toxic waste gases. The underlying mechanisms governing these applications, as resulting from the interaction between the plasma and the catalyst, rend...

/pdf/plasma-catalysis-synergistic-effects-at-the-nanoscale-2aaod3plcw.pdf

Plasma Catalysis: Synergistic Effects at the Nanoscale

A hologram forming layer, transparent evaporated layer, colored layer, adhesion anchor layer, and adhesive layer are sequentially laminated on the under surface of a base member. The laminated body is used as a seal by the presence of the adhesive layer. It is preferable for the base member to have adequate rigidity (flexibility, tensile strength) and surface flatness. The hologram forming layer has a relief type hologram image. The transparent evaporated layer is a multi-layered ceramic layer constructed by alternately laminating high-refractive index layers and low-refractive index layers and the thickness thereof is preferably set to 1 μm or less. In the transparent evaporated layer, the color of visible light in predetermined wavelength range is changed according to the viewing angle when it is transmitted therethrough or reflected therefrom.

Transparent hologram seal

The synthesis of ammonia from nitrogen-hydrogen plasma prepared using radiofrequency discharge and microwave discharge was studied under the same experimental conditions except the driving frequency. Twice larger amounts of ammonia were adsorbed on zeolite used as adsorbent in the microwave discharge than in the radiofrequency discharge. Relative intensities of NH band head (A3Π−X3Σ−,0−0) as well as hydrogen atomic line (H\) observed in the plasma prepared using microwave discharge were one order of magnitude larger than those in the plasma prepared using radiofrequency discharge. Since NHx radicals and H atoms are considered ammonia precursors, the advantage of microwave discharge over radiofrequency discharge on ammonia synthesis is discussed from the results obtained above and from the plasma parameters,kT

 e
 andn

 e
 , obtained by the electric double probe technique.

Synthesis of ammonia in high-frequency discharges

The catalytic effect of iron wires on plasma syntheses of ammonia and hydrazine has been studied in the nitrogen-hydrogen plasma prepared using rf discharge at a pressure of 650 Pa (5 Torr). The product was mainly ammonia including a small amount of hydrazine. When iron wires were placed in the plasma downstream of the gas flow, the yields of both products increased, about two times in ammonia and two orders of magnitude in hydrazine. The yields increased with increasing number of wires (the surface area of the catalyst). The dissociative adsorption of nitrogen molecules and/or molecular ions on the iron surface and the formation of NHx by the reaction with hydrogen in the plasma followed by the formation of NH3 or N2H4 are considered as a reaction scheme. This is supported by the identification of NH3 with XPS of the surface of iron wires.

Catalytic effect of iron wires on the syntheses of ammonia and hydrazine in a radio-frequency discharge

The synergistic effects o1 driving frequency of the discharge and catalysis of iron and molybdenum wires when then are placed in nitrogen-h ydrogen radio-frequency and microwave plasmas mere investigated. The ammonia Yield increased in the plasmas prepared using both driving frequencies. but the hydrazine yield increased only in fire radio-frequency discharge with the catalysts. The direct adsorption of NHx formed in the plasma on the catalyst surface followed by the formation of NH3 and N2H4 are considered as a reaction scheme in the radio-frequency discharge. On the other hand, the adsorption of N atoms and/or formation of the metal- N bond favors the formation of ammonia but does not affect the hydrazine formation in the microwave discharge.

Synergistic effects of catalysts and plasmas on the synthesis of ammonia and hydrazine

The synthesis of ammonia from nitrogen-hydrogen plasma prepared using microwave discharge was studied by changing some experimental conditions, such as pressure (260–2600 Pa), power input (30–280 W), and nitrogen-hydrogen mixing ratio [H2/(N2+H2)=0−1.0]. The ammonia yield increased with decreasing pressure and saturated at lower pressures. When the power input and the nitrogen-hydrogen mixing ratio were changed, the maximum yield of ammonia was obtained at the optimum experimental conditions (power input ≈150W; H2/(N2+H2)≈0.75). Amounts of NH, H, and H2 in the plasma also changed by changing the experimental conditions. From the changes in ammonia yield and amounts of NH, H, and H2 by changing the experimental conditions, it is suggested that ammonia molecules are formed by the reaction of NH radicals not only with hydrogen atoms but also with hydrogen molecules. Otherwise, the formation and the decomposition of ammonia would occur simultaneously.

Haruo Uyama

Papers

Transparent hologram seal

Synthesis of ammonia in high-frequency discharges

Catalytic effect of iron wires on the syntheses of ammonia and hydrazine in a radio-frequency discharge

Synergistic effects of catalysts and plasmas on the synthesis of ammonia and hydrazine

Synthesis of ammonia in high-frequency discharges. II. Synthesis of ammonia in a microwave discharge under various conditions