Studies On The Application Of Niobic Acide In Organic Synthesis

The reactions of the dehydration of the cyclopentene and cyclohexenethe, the esterification of p-tert-Butylbenzoic acid with methy alcohol and the isomerization of Sassafras Oil over Nb2O5-nH2O catalyst were studied. The effects of the calcination temperatures, the modification through impregnating with acid and the structure of the crystallization of Nb2O5-nH2O catalyst were investigated. The surface acid properties and catalytic activities of the catalyst were characterized by XRD, NH3-TPD, Py-IR, TG/DTA, BET.The results showed that Nb2O5-nH20 was effective for the reactions of dehydration and esterification, and the conversion of the reactions was about 85%, the selectivites was up to 100% under proper operation conditions. The active sites and acid strength on the surface of the heat-treated Nb205-nH2O. catalyst varied with the different modifying temperatures. The treatment of impregnating with acid could increase the activities of the catalyst. But its crystal structure had no effect on the activity of Nb2O5'nH2O.