高温域における高純度水素分離に適したプロトン導電体SrZr<SUB>1-x</SUB>Y<SUB>x</SUB>O<SUB>3-α</SUB>の作製

Abstract

The SrZr1-xYxO3-α of proton conductor was prepared by normal sintering and SPS (spark plasma sintering) methods in order to separate pure hydrogen gas from H2-containing mixed gases in high temperature range. The SrZr1-xYxO3-α has high proton conductivity under H2 gas atmosphere from 973 K to 1273 K. In this hydrogen separation system, hydrogen is oxidized to proton at the anode, and proton is reduced to hydrogen at the cathode using proton conductor by electrochemical method. Proton conductors SrZr0.9Y0.1O3-α obtained by normal sintering at 1580°C for 10 h and SPS at 1500°C for 3 min were found to be single phase of perovskite structure. Furthermore, the crystal structure of SrZr0.9Y0.1O3-α was chemically stable under H2 and CO2 gases atmosphere. Relative densities of SrZr0.9Y0.1O3-α obtained by SPS at 1400 and 1500°C were over 95 %. Furthermore, the relative density increased with sintering temperature and time of SPS. The proton conductivity of SrZr0.9Y0.1O3-α of SPS increased with sintering temperature, and was higher than one of normal sintering under wet 10 % H2 and Ar gases atmosphere. From the measurement of EMF (electromotive force) of hydrogen concentration cell at 800°C, the ionic transport number of SrZr0.9Y0.1O3-α of SPS at 1400°C for 5 min was about 1, and the electron conductivity was considerably low.