Ru-Ir双金属催化剂制备及其催化氯代硝基苯加氢反应的研究

采用浸渍法制备了系列负载型Ru-Ir双金属催化剂,用于催化对氯硝基苯的选择加氢。系统考察了不同制备方法和制备条件对催化剂性能的影响。实验结果表明,以-γA l2O3为载体,用异丙醇共浸渍钌和铱,氢压为4.0 MPa,温度180℃,用氢气还原18 h制备的双金属Ru-Ir催化剂（nRu∶nIr=4∶1,担载量为2.0%）具有较好的催化性能。该催化剂用于对氯硝基苯加氢还原反应中,在反应温度60℃,氢气压力为2.0 MPa,底物与催化剂的摩尔比为1 000∶1条件下,反应1 h,转化率可达90.4%,目标产物对氯苯胺的选择性达99.5%。

Preparation of Ru-Ir bimetallic catalysts and catalytic hydrogenation of chloronitrobenzene

Series of bimetallic Ru-Ir catalyst were prepared by impregnating carriers and were used in the selective hydrogenation of chloronitrobenzene.The performance of catalyst on the different preparation methods and conditions were systematically investigated.Experimental results showed that γ-Al2O3 as the carrier,impregnating ruthenium and iridium with isopropanol,the preparation conditions of hydrogen pressure 4.0 MPa,temperature 180 ℃ for 18 hours,the bimetallic Ru-Ir catalyst（nRu∶nIr = 4∶1,and loadings of 2.0%） exhibited excellent catalytic properties.In the presence of the Ru-Ir/γ-Al2O3 catalyst,the conversion of p-CNB was 90.4% and the selectivity to p-chloroaniline（p-CAN） was up to 99.5% under the conditions of 60 ℃ of reaction temperature,1 hour of reaction time,2.0 MPa of H2 pressure,and 1 000∶1 molar ratio of substrate to metal.