反应详情

Yttrium nitrate hexahydrate 95.7 g was dissolved in 1000 g of water, to form an aqueous solution of yttrium nitrate. The solution was heated to 80° C. with stirring, into which 500 g of 25% aqueous ammonia was added dropwisely over 2 hours. Stirring was continued for further 5 hours at 80° C., to form an yttrium hydroxide slurry. The slurry was filtered and washed thoroughly with pure water until pH of the filtrate became neutral. Thus, hydrous yttrium hydroxide was obtained. The yttrium hydroxide was dried in air at 120° C., followed by a sequential calcining in air at 500° C. for 5 hours and in nitrogen at 500° C. for 5 hours. The yttrium oxide whereby obtained was labelled Catalyst (1), which had a specific surface area of 58 m2 /g.