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用浸渍法制备的负载铱催化剂催化间二硝基苯部分加氢制间硝基苯胺,考察了温度对反应的影响和催化剂循环实验,结果表明,催化剂活性在90℃最佳;间硝基苯胺选择性随温度升高而增加.以甲醇作溶剂,在n(substrate) /n(Ir) =5000, 90℃, 0.8 MPa条件下,反应1 h,间二硝基苯转化率100%,间硝基苯胺选择性96.3%,全部加氢产物间苯二胺很少生成.催化剂经3次循环,活性下降不明显,在第6次循环时延长反应时间至2.5 h,间二硝基苯转化率和间硝基苯胺选择性均能达到100%.催化机理有待进一步研究.
The supported iridium catalyst prepared by the impregnation method was used to catalyze the partial hydrogenation of m-dinitrobenzene to the m-nitroaniline. The effects of temperature on the reaction and catalyst cycling were investigated. The results showed that the catalyst activity was the best at 90 ℃. Selectivity increased with increasing temperature.Using methanol as solvent, the reaction was carried out at n (substrate) / n (Ir) = 5000, 90 ℃ and 0.8 MPa for 1 h, the conversion of m-dinitrobenzene was 100% Nitroaniline selectivity 96.3%, all of the hydrogenation product m-phenylenediamine rarely generated catalyst after 3 cycles, the activity was not significantly reduced at the 6th cycle to extend the reaction time to 2.5 h, m-dinitrobenzene conversion The rate and the selectivity of m-nitroaniline can reach 100%. The catalytic mechanism needs further study.