著者
杉本 栄佑 幸塚 善作
出版者
一般社団法人 資源・素材学会
雑誌
日本鑛業會誌 (ISSN:03694194)
巻号頁・発行日
vol.104, no.1200, pp.89-95, 1988
被引用文献数
2

The present study was done for the purpose of finding any available solid reference electrode for SO<SUB>2</SUB>sensor employingbeta alumina solid electrolyte. In this paper, we tried a few experiments for this sensor using two solid reference electrode, (&beta;+&beta;')-alumina and (&alpha;+&beta;)-alumina.<BR>The cells used were as follows: Pt, (&beta;+&beta;')-alumina in air/&beta;'-alumina/Na<SUB>2</SUB>SO<SUB>4</SUB>/SO<SUB>2</SUB>+O<SUB>2</SUB>+SO<SUB>3</SUB>, Pt (1) Pt, (&alpha;+&beta;)-alumina in air/&beta;-alumina/Na<SUB>2</SUB>SO<SUB>4</SUB>/SO<SUB>2</SUB>+O<SUB>2</SUB>+SO<SUB>3</SUB>, Pt (1)(11) From the present experiments, the following conclusions were obtained.<BR>1) The constant sodium activities in these solid reference electrodes were maintained for a long duration of the experiment.<BR>2) For both cells, good straight lines were obtained between e.m.f.'s and log Pso2 within the temperature ranges from 933 to 1230 K in the cell (1) and from 932 to 1278 K in the cell (11). Especially, in the (&beta;+&beta;')-alumina solid reference electrode, it was shown that the cell using this electrode could be employed to determine concentrations up to a few ppm of SO<SUB>2</SUB> gases at temperatures of 932 to about 1100 K. Consequently, this (&beta;+&beta;')-alumina mixture is recommended for the solid reference electrode ofSO<SUB>2</SUB> sensor employing&beta;'-alumina solid electrolyte.<BR>3) From e.m.f.'s of these cells, the activities of Na<SUB>2</SUB>O in &beta;-Al<SUB>2</SUB>O<SUB>3</SUB>+&beta;'-Al<SUB>2</SUB>O<SUB>3</SUB>and &alpha;-Al<SUB>2</SUB>O<SUB>3</SUB>+&beta;-Al<SUB>2</SUB>O<SUB>3</SUB>coexistences were respectively calculated by considering thermochemical data and compared with the others.