Nb2O5/坡缕石固体酸催化合成偏苯三酸三辛酯

Catalyzed Synthesis of Trioctyl Trimellitate by Nb2O5/ Palygorskite Solid Acid

摘要:

利用离子交换法将Nb5+引入坡缕石(Nb5+/PG)，经300 °C培烧后得坡缕石负载Nb2O5的固体酸 （300-Nb2O5/PG），利用X-射线衍射、X-射线光电子能谱、紫外漫反射、N2吸附-脱附(BET)、ICP、NH3-TPD对其结构、金属含量、酸强度进行表征。在催化合成偏苯三酸三辛酯(TOTM)中，当偏苯三酸酐与2-乙基己醇的摩尔比为1︰4，300-Nb2O5/PG用量为酸酐质量的5%，210 °C，反应5 h后，偏苯三酸三辛酯酯化率可达到95.3%，催化剂重复使用10次后，酯化率89.2%。

Abstract:

The palygorskite was ion-exchanged with NbCl5 and calcined at 300°C to prepare solid acid of palygorskite supported Nb2O5 (300-Nb2O5/PG). This modified palygorskite was characterized by XRD, XPS, UV–Vis, N2 adsorption/desorption, ICP and NH3-TPD. The material was used in the esterification of trioctyl trimetabenzoate (TOTM) as catalyst. The esterification yield of trioctyl trimetabenzoate was 95.3% at 210°C to reflux 5 h when catalyst amount was 5 wt. % of trimellitic anhydride, trimellitic anhydride: 2-ethyl hexanol = 4:1(mol/mol). The esterification yield was 89.2% when the catalyst was reused ten times.