| NUKLEONIKA 2006, 51(Supplement 1):s79-s82
APPLICATION OF Pt/Al2O3 CATALYSTS PRODUCED BY SOL-GEL PROCESS TO URANYL ION REDUCTIONAndrzej Deptuła, Wiesława Łada, Tadeusz Olczak, Andrzej G. Chmielewski Institute of Nuclear Chemistry and Technology, 16 Dorodna Str., 03-195 Warsaw, Poland Various kinds of active alumina supports were obtained by the Institute of Nuclear Chemistry and Technology (INCT) sol-gel process 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 mm) by extraction of water from sol emulsion in 2-ethyl-1-hexanol; (3) sometimes conversion of NO3- stabilized gel to OH- form by reaction with ammonia; (4) calcination of gels to g-Al2O3 with specific surface area >100 m2/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/Al2O3 catalysts were used for the reduction of 1 M UO2(NO3)2- 0.5 M 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 the supports prepared from nitrate stabilized gels exhibit the best activity and stability. Close X |