摘要
用XRD、BET和TG/DTG对铌酸的结构特征和表面酸强度进行了分析。结果表明,经酸处理的铌酸具有明显的晶体结构,其表面酸强度依次为:经硝酸及磷酸处理的铌酸>硝酸处理的铌酸>水洗的铌酸。研究了(硝酸+磷酸)处理的铌酸对制备油酸甲酯催化反应活性的影响,并对此酯化反应合成条件进行了考察。试验结果表明,铌酸对催化油酸和甲醇的酯化反应具有较好的活性和稳定性。适宜酯化反应条件:反应温度180℃,醇酸摩尔比为2.0,反应时间4.0 h,催化剂用量为原料质量的9.10%。
The structure and surface acidity of the niobic acids were analyzed by XRD,BET and TG/DTG.The results showed that the niobic acid treated with the other acid had obvious crystal structure and higher surface acid strength.Treatment of niobic acid with nitric acid and phosphoric acid affected the catalytic activity in synthesis of methyl oleate from oleic acid and the methyl alcohol.The experimental results indicated that niobic acid had a better catalysis performance and stability.The optimal esterification reaction condition are as follows：reaction temperature（180 ℃,） methanol-acid molar ratio 2∶1,reaction time 4.0 h,catalyst amount used for raw material 9.10%（weight ratio）.Niobic acid is an ideal solid acid catalyst for this reaction.
出处
《化学工业与工程》
CAS
2008年第6期519-522,共4页
Chemical Industry and Engineering
关键词
固体酸
铌酸
酯化反应
油酸甲酯
solid acid
niobic acid
esterification
methyl oleate
