Papers by Keyword: Oxygen Gas Concentration Cell

Abstract: C-Ru-RuO2 nano-composite films were prepared by plasma-enhanced chemical vapor deposition and their microstructure and electrode properties were investigated. Ru-C nano-composite films consisted of Ru nano-particles of 3 nm in diameter and an amorphous C matrix. With increasing oxygen gas flow rate (FRO2), the volume fraction of C decreased from 0.91 to 0 and Ru nano-particle size increased from 2.5 to 4.5 nm. At high FRO2, the film consisted on the fibrous RuO2 and Ru-C nano-composite layer. Ru-C nano-composite containing 91 vol% C showed the highest interfacial electrical conductivity below 673 K, and Ru-C/RuO2 composite containing 0 – 5 vol% C showed the highest interfacial electrical conductivity at 873 K. Electro-motive-force (EMF) values of an oxygen concentration cell constructed from a YSZ electrolyte and Ru-C or Ru-C/RuO2 composite electrodes responded to the change of oxygen gas partial pressure at more than 473 K. The response time of the concentration cell with Ru-C nano-composite electrodes at 573 K was less than 10 s, and that with Ru-C/RuO2 composite electrodes was about 300 s.

Abstract: Ruthenium-Carbon (Ru-C) nano-composite films were prepared by microwave-induced plasma-enhanced chemical vapor deposition (PECVD) and the effects of deposition conditions on the microstructure and electrical properties were investigated. The films consisted of agglomerated grains of 10 to 20 nm in diameter, in which Ru particles of 2.5 to 3.5 nm in diameter were dispersed in an amorphous C matrix. The C contents of the films ranged from 86 to 94 vol%. The electrical properties of Ru-C nano-composite films as a catalytic electrode for an yttria-stabilized zirconia (YSZ) solid electrolyte were evaluated by AC impedance spectroscopy. The electrical conductivity at the Ru-C/YSZ interface (σi) was 0.2 × 10-3 Sm-1 at 500 K and increased with increasing temperature. The activation energy of the σi was 70 kJ/mol. Electro-motive-force (EMF) values of an oxygen concentration cell constructed from YSZ electrolyte and Ru-C nano-composite electrodes responded to the change of oxygen partial pressure above 473 K. The response time of the concentration cell was less than 10 s above 573 K.