| 초록 |
NH4+/H3O+-β"-aluminas were synthesized from the K+-β"-alumina precursor by a ion exchange reaction. In the autoclave reaction, the potassium concentration was varied within the molar ratio range, [K2O] : [Al2O3] = 1 : 4 ~ 1 : 8, and the concentration of NH4NO3 solution was chosen at 1 M and 2 M. The exchange reaction was carried out at 130, 150 and 180 ℃ for 2, 4, 6, 8 and 24 h. In the heating mentle reaction, molten NH4NO3 salt was used and the reaction temperature/time were 180 ℃, 200 ℃ and 2~48 h. The highest ion exchange rate were observed in the autoclave : 90 %, in the heating mentle : 98 %, respectively . The phase stability and transformation were confirmed by XRD, and the ion exchange rate was analyzed by ICP-AES. |
