铌酸改性及催化合成油酸异丁酯

Modification and Application of Niobic Acid Catalysis in Synthesis of Tebelon

摘要: 本文采用氢氧化钾熔融酸化法合成了四种改性铌酸，利用XRD、氮气吸脱附曲线和NH₃-TPD等考察了改性铌酸的结构特征和表面酸性，同时考察其在油酸和异丁醇催化合成油酸异丁酯中的催化反应活性，对合成条件进行了优化。试验结果表明，硫酸改性后的铌酸具有较好的催化反应性能和良好的稳定性。适宜酯化反应条件为硫酸改性铌酸催化剂，催化剂用量为原料质量的1.0%，反应温度110℃，异丁醇与油酸摩尔比2:1和反应时间8小时。

Abstract: Four kinds of modified niobic acids were synthesized by potassium hydroxide melting method using different inorganic acid treatments. The structure and surface acidity of this niobic acid were studied by XRD, N₂ adsorption-desorption and NH₃-TPD. The catalytic activity of modified niobic acid in the synthesis of tebelon had been studied. The experimental results indicated that H₂SO₄-Nb₂O₅ has the better performance and stability. The optimal conditions of etherification reaction are as follows: catalyst amount used for raw material 1.0% (weight ratio), reaction temperature 110˚C, mole ratio of alcohol to acid 2:1 and reaction time 8 h.