磷钨酸改性UiO-66催化对二甲苯的乙酰氧基化和硝化同步反应

Simultaneous Acetoxylation and Nitration of P-xylene over UiO-66 Modified by Phosphotungstic Acid

采用溶剂热法一步合成不同磷钨酸含量的UiO-66催化剂,对催化剂进行XRD、FT-IR及氮吸附表征,探索改性催化剂的结构,研究催化剂对二甲苯的乙酰氧基化和硝化反应的催化性能;考察催化剂种类、用量和反应温度对反应的影响,推测反应机理。结果表明:40℃下,采用0.2 g磷钨酸改性UiO-66,NO_(3)^(-)和对二甲苯的物质的量比1:1;催化剂的用量为80%时,催化效果最优。在该条件下,对二甲苯的催化反应的总产率为91.02%,乙酰氧基化产物的产率为38.16%,硝化产物的产率为52.86%。

The UiO-66 catalysts with different amount phosphotungstic acid were synthesized by solvent thermal method in one step.The catalysts were characterized by XRD,FT-IR and N_(2) adsorption-desorption to explore the structure of modified catalysts.The amount of catalyst,the kinds of catalysts and reaction temperature was studied in the reaction of acetoxylation and nitration of p-xylene and the reaction mechanism was speculated.The results showed that at 40℃,UiO-66 catalyst modified by 0.2 g phosphotungstic acid was used,n(NO_(3)^(-)):n(p-xylene)=1:1,and the amount of catalyst was 80%,the optimal reaction conditions was obtained.Under these conditions,the total yield of catalytic reaction of p-xylene was 91.02%,the yield of acetyl oxidation product was 38.16%,and the yield of nitration product was 52.86%.