水溶性Ru-TPPTS配合物催化对-氯硝基苯选择性加氢

Selective hydrogenation of p-chloronitrobenzene catalyzed by water-soluble Ru-TPPTS complex

研究了水/有机两相催化体系中,水溶性Ru-TPPTS配合物催化对-氯硝基苯中硝基的选择性加氢反应。考察了溶剂种类、水溶液的pH值、添加助剂三乙胺、水/有机两相体积、底物浓度等对对-氯硝基苯转化率和生成对-氯苯胺选择性的影响,并在90℃、4.OMPa、反应时间为6h的条件下,进行了催化剂的循环实验。

Selective hydrogenation of p - chloronitrobenzene catalyzed by water - soluble Ru - TPPTS complex AC - 1. lin the bi- phasiecatalytic system（ aqueous/organic phase）has been studied. The influences of reaction conditions, such as different solvents, aqueousphase pH value, triethylamine, volume ratio of aqueous and organic phase and substrate concentration, on the activity and selectivity have been investigated systematically. It has been found that the reaction rate was obviously accelerated by polar solvents, with toluene and chlorobenzene performing the best. The reaction rate was obviously promoted after the addition of triethylamine. It is also found that the catalytic activity grew rapidly in accordance with the raised aqueous pH value. Nevertheless, the selectivity quickly goes went down alter the aqueous phase pH value 〉 9 ; and the ratio of the aqueous/organic phase also influenced the reac- tion. Under theconditions with temperature of 90℃, H2 pressure of 4.0 Mpa, andreactwn time of 6h, the conversion of p - ClC6H4NO2remained high after the first time recycle of the catalyst, But it decreases to 59.7% through three times recycle.