摘要
研究了煤质炭负载杂多酸催化剂对邻苯二酚和乙醇的O 乙基化反应的催化性能 .发现相同负载量的Keggin型磷钨酸催化剂的活性远高于硅钨酸和Dawson型磷钨酸 ;负载杂多酸催化剂上邻乙氧基苯酚的选择性明显高于磷酸催化剂 .采用BET ,XRD及TPD技术对催化剂进行了表征 ,并考察了Keggin型磷钨酸的负载量和反应温度对催化性能的影响 .
The vapor-solid phase O-ethylation of catechol with ethanol to produce o-ethoxyphenol was investigated over three heteropoly acids (HPA) supported on activated carbon (AC). BET and XRD results indicated that three HPAs were almost uniformly dispersed on the exterior surface of AC. NH_3-TPD results showed that the acid strength of Keggin phosphotungstic acid (PW_ 12) supported on AC was weaker than that of silicotungstic acid (SiW_ 12) and Dawson phosphotungstic acid (P_2W_ 18) supported on AC with the same loading amount. The O-diethylated product (o-diethoxybenzene) was almost not detected in the products by GC over HPA catalysts. Compared with phosphoric acid supported on AC, the selectivity for o-ethoxyphenol was higher over HPA catalysts. Among the three HPA catalysts with 12% loading amount, the PW_ 12/AC catalyst gave the highest conversion of catechol. The influence of the loading amount and reaction temperature on catalytic activity of PW_ 12/AC was also investigated and it was found that with 12% loading amount at 260 ℃, 73.8% conversion of catechol and 96% selectivity for o-ethoxyphenol were obtained. The conversion of catechol decreased gradually with the reaction time prolonging within 10 h.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第2期103-106,共4页
基金
吉林省科技厅资助项目 ( 990 5 46)
