(大連交通大學(xué) 材料科學(xué)與工程學(xué)院 無(wú)機(jī)超細(xì)粉體制備及應(yīng)用遼寧省重點(diǎn)實(shí)驗(yàn)室，大連 116028)
摘 要: 采用水熱法，以硫酸鋁 (Al2(SO4)3？18H2O)為原料、尿素為沉淀劑，在一定的醇水比例下(體積比2:1)，制備出具有不同形貌的氧化鋁前驅(qū)體，用SEM、XRD和TG-DSC分析對(duì)粉體的微觀結(jié)構(gòu)及熱分解過(guò)程進(jìn)行了研究。結(jié)果表明：相同條件下，水熱處理溫度影響氧化鋁前驅(qū)體的微觀形貌及向α-Al2O3轉(zhuǎn)變的溫度，隨水熱處理溫度的提高，其相結(jié)構(gòu)由無(wú)定型態(tài)向結(jié)晶度高的薄水鋁石相轉(zhuǎn)變，而其煅燒產(chǎn)物向α-Al2O3轉(zhuǎn)變的溫度逐漸升高。利用Doyle-Ozawa法和Kissinger法計(jì)算經(jīng)水熱溫度為100、140和160 ℃處理獲得產(chǎn)物熱分解過(guò)程的表觀活化能，通過(guò)該兩種方法得到的表面活化能平均值分別為150.68、155.46、171.09 kJ/mol。用 Kissinger 法確定了反應(yīng)級(jí)數(shù)、頻率因子和不同水熱處理溫度下產(chǎn)物的熱分解速率方程。
關(guān)鍵字: 氧化鋁前驅(qū)體；熱分解；表觀活化能；Doyle-Ozawa法；Kissinger法
（Liaoning Key Laboratory for Fabrication and Application of Superfine Inorganic Powders,
Faculty of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, China）
Abstract:Alumina precursors with different morphologies were synthesized using Al2(SO4)3·18H2O as reactant, urea as precipitator and mixture solution of ethanol and water (volume ratio of 2:1) as solvent by a hydrothermal treatment method. The microstructures, thermolysis processes of as-synthesized powders were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), differential scanning calorimeter and thermo gravimetric analysis(TG-DSC). The results show that, under the same conditions, hydrothermal temperature affects the morphology of the alumina precursor and the phase transition temperature of α-Al2O3. With increasing the hydrothermal temperature, their phases change from amorphous to boehmite with high crystallinity, at the meantime, the phase transition temperature of α-Al2O3 of their calcined products increase gradually. The average apparent activation energies of thermolysis of precursors obtained on three hydrothermal temperature 100, 140 and 160 ℃ are calculated to be 150.68、155.46 and 171.09 kJ/mol, using the Doyle-Ozawa and Kissinger methods, respectively. The reaction order and frequency factor are determined by Kissinger method. The kinetics equations of thermolysis of precursors obtained at different hydrothermal temperatures are deduced.
Key words: alumina precursor; thermolysis; apparent activation energy; Doyle-Ozawa method; Kissinger method
