Keggin型磷钨酸镧催化环己酮自缩合反应

Self-Condensation of Cyclohexanone over Keggin Type Lanthanum Phosphotungstate Catalyst

合成了Keggin型磷钨酸镧(LaPW12O40),并以LaPW12O40为催化剂催化环己酮进行自缩合反应合成了环己酮二聚物(环己基环己酮、环己烯基环己酮)。采用傅里叶变换红外光谱和31P核磁共振等方法表征了LaPW12O40的结构,表征结果显示,LaPW12O40具有Keggin型结构。以环己酮为原料、LaPW12O40为催化剂制备了环己酮二聚物,考察了催化剂用量、带水剂种类及用量、反应时间、反应温度等条件对环己酮自缩合反应的影响。实验结果表明,以环己烷为带水剂的效果很好。在LaPW12O40用量0.20mmol、环己烷用量15mL、反应时间6h、反应温度130℃的优化反应条件下,环己酮的转化率为74.9%、环己酮二聚物的选择性为97.3%。

Keggin type lanthanum phosphotungstate（LaPW12O40） catalyst was prepared and used in self-condensation of cyclohexanone to produce dimer-cyclohexanone （cyclohexyl-cyclohexanone, cyclohexenyl-cyclohexanone）. The catalyst was characterized by means of FTIR, 31p NMR and was proved to be of Keggin type structure. Effects of catalyst dosage, water entrainer type and dosage, reaction time and reaction temperature on self-condensation of cyclohexanone were investigated. Cyclohexane was chosen as a good water entrainer. Under optimum conditions： catalyst dosage 0.20 mmol, cyclohexane dosage 15 mL, reaction time 6 h and reaction temperature 130 ℃, conversion of cyclohexanone and selectivity to dimer-cyclohexanone are 74.9% and 97.3% respectively.