Preparation of Pt/Al{sub 2}O{sub 3} catalysts by sol-gel process and its application to uranyl ion reduction
- Inst. of Nuclear Chemistry and Technology, Warsaw (Poland)
- ENEA, Rome (Italy). C.R.E. Casaccia
Various kinds of active alumina supports were obtained in the following steps: (1) preparation of alumina sols by extraction of nitrates with Primene JMT from aluminium nitrate solution, (2) gelation to spherical particles (with diameter < 100 {mu}m) by extraction of water from sol emulsion in 2-ethyl-1-hexanol, (3) sometimes conversion of NO{sub 3}{sup {minus}} stabilized gel to OH{sup {minus}} form by reaction with ammonia, (4) calcination of gels to {gamma}-Al{sub 2}O{sub 3} with specific surface area > 100 m{sup 2}/g at 500 C. The powders were then impregnated with chloroplatinic acid and recalcined at 500 C. Catalysts were also prepared by direct gelation of alumina sol containing hydroplatinic acid followed by steps (3) and (4). Pt/Al{sub 2}O{sub 3} catalysts were used for reduction of 1M UO{sub 2}(NO{sub 3}){sub 2}- 0.5M HCOOH solution with hydrogen at atmospheric pressure. The course of the reduction was controlled analytically and by measuring the U(VI)/U(IV) redox potential. It was concluded that the catalysts obtained by impregnation of supports prepared from nitrate stabilized gels exhibit the best activity and stability.
- OSTI ID:
- 51628
- Report Number(s):
- CONF-940411--; ISBN 1-55899-246-4
- Country of Publication:
- United States
- Language:
- English
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