Electrocatalysts Based on Platinized Titanium Dioxide Doped with Ruthenium for Hydrogen and Carbon-Monoxide Potentiometric Sensors

The electrocatalysts based on platinized TiO₂(Ru) oxides with different ruthenium content are studied as the working electrode in solid-state potentiometric sensors for H₂ and CO. Increasing the ruthenium content does not affect the size of platinum particles, but reduces its content in the metallic state. The results of X-ray diffraction, X-ray fluorescence, and scanning electron microscopic studies are presented. The synthesized electrocatalysts are tested as the working-electrode materials in hydrogen and carbon monoxide sensors for the gas concentration in the air flow from 1 to 50 000 ppm. The characteristics of the sensors are shown to depend on the oxide support composition and structure. The electrocatalysts with the rutile structure are recommended for the practical use; the ruthenium content is determined by the range of analyzed CO concentrations.