碳酸二乙酯与苯酚催化合成苯乙醚的研究

实验以负载型固体碱KOH/活性炭为催化剂,使碳酸二乙酯与苯酚进行液相乙基化反应合成苯乙醚。以CO_2程序升温脱附法(CO_2-TPD)对催化剂的碱量和碱强度进行表征。实验结果表明,以KOH为活性组分(负载量20%),活性炭为载体的催化剂对碳酸二乙酯和苯酚的乙基化反应活性最高。考察了催化剂用量、反应温度、原料配比、反应时间对该反应的影响,适宜的反应条件为:反应温度130℃,催化剂占原料总质量分数的5%,n(DEC):n(苯酚)=2:1,反应时间150 min,在此条件下,苯酚的转化率和苯乙醚的选择性分别为99.6%和98.2%。

CATALYTIC SYNTHESIS OF PHENETOLE BY ETHYLATION OF PHENOL WITH DIETHYL CARBONATE

O-ethylation of phenol with diethyl carbonate as an alkylating agent in liquid phase has been conducted to synthesize phenetole over KOH/Active Carbon(AC)catalyst.CO_2-TPD is used to characterize the basic properties of the catalysts.Characterization results indicate that the number of the weakly acidic sites increase with increasing the amount of KOH with the maximum over 20%KOH/AC.The weakly basic sites of KOH/AC may be the active centers for O-ethylation of Dhenol with diethyl carbonate.20%KOH/AC catalyst also exhibits the highest activity for the O-ethylation of phenol with diethyl carbonate.In addition,effects of catalysts dosage,temperature,n(DEC);n(phenol)and reaction time are investigated.Under the optimal reaction conditions,i.e.,temperature 130℃.catalyst dosage 5%,n(DEC):n(phenol)=2:1 and 150 min,phenol conversion and selectivitv to phenetole are 99.6%and 98.2%,respectively.