【摘要】 从钼磷酸出发制备了Ｂｉ４ＰＭｏ１２Ｏ４９催化剂．ＩＲ及ＸＲＤ分析结果表明，高温焙烧后其基本组成为α－Ｂｉ２Ｍｏ３Ｏ１２／ＭｏＯ３。考察了该催化剂对丙烷的选择氧化活性．ＥＳＲ及ＸＰＳ测定结果表明，反应后催化剂中Ｍｏ５＋的含量明显增加．这暗示着反应物种吸附在Ｍｏ６＋上，而Ｂｉ则为气相氧的入口．更多还原

【Abstract】 i4PMo12O49, catalyst was prepared from 12-molybdophosphoric acid in acidic condition. The basic compositioll of calcinated catalyst,α-Bi2Mo3O12/MoO3, was determined by means of IR and XRD. The selective oxidation of propane over the catalyst was investigated. It was found that the characteristic peaks of Keggin structure, 1062 cmAil and 960 cm-1, of 12-molybdophosphoric acid decreased and disappeared when the calcination temperature was higher than 420℃. This indicates that the structure of the heteropoly acid decomposed completely, and the structure of the Bi/Mo catalysts became stable. In IR spectrum of 12-molybdophosphoric acid calcinated at 520℃, the 1097. 7 (m), 989. 8(s), 867. 6 (s), 818. 9(w), 670. 7(s), 654. 3(sh), 506. 6(w) and 480(w) cm-1 peaks can be found, and the absorption bands at 867.6, 818. 9 band 989. 9 cm-1are attributed to the characteristics of MoO3. When bismuth was added to the catalyst, the characteristic absorption bands of α-Bi2Mo3O12, at 953. 6,933. 6 and 900. 3 cm-1 appeared. In the XRD spectra, the corresponding peaks attributed to MoO, (d = 3. 2426 ) and α-Bi2Mo3O12 (d = 3. 1839,3. 0516 and 2. 8624) also appeared. The strongest peak, d= 3. 1839, was appointed to the species resulting from the co-effect of α and β phase, and the peaks for β and γ phase were too weak to be found. So we could conclude that the main component of the catalyst was α-Bi2Mo3O12/MoO3,and the activity of the catalyst resulted possibly from the co-effect of these two phases. The results of ESR and XPS indicated that the amount of Mo5+ increased after reaction. This implied that the reactant is adsorbed on Mo6+, and Bi is the entrance for O2.更多还原