钯基合金催化剂制备及其选择性加氢性能研究

Preparation of Palladium⁃Based Alloy Catalysts and Performance of Selective Hydrogenation

李培才 王宁 白树行

Peicai Li Ning Wang Shuxing Bai

青岛大学 化学化工学院，山东 青岛 266071

School of Chemistry and Chemical Engineering，Qingdao University，Qingdao Shandong 266071，China

为解决钯（Pd）催化剂在选择性加氢中对目标产物选择性差的问题，添加第二金属M（M为Mn、Fe、Co、Ni），通过简单共还原法合成了PdM/C双金属合金催化剂；以3?硝基苯乙烯为模型分子，以H2作为氢源，研究了第二金属对Pd基催化剂选择性加氢性能的影响规律；采用XRD、TEM、气相色谱等方法对Pd基催化剂进行了表征与测试。结果表明，以纯Pd/C为催化剂，3?硝基苯乙烯加氢反应1.5 h，其转化率为100%，3?硝基苯乙烷的选择性仅为29%，过度加氢产物3?氨基苯乙烷的选择性为71%；引入第二金属后，PdM/C对3?硝基苯乙烷的选择性提升到75%~100%。其中，PdFe/C能将3?硝基苯乙烯完全加氢转化成3?硝基苯乙烷，且反应10次后，3?硝基苯乙烯的转化率仍保持在100%，3?硝基苯乙烷的选择性为99%，能够有效地避免过度氢化，实现3?硝基苯乙烯选择性加氢制备3?硝基苯乙烷。

As palladium(Pd) catalysts have poor selectivity to the target product in the selective hydrogenation process,a series of PdM/C bimetallic alloy catalysts were synthesized by the simple co?reduction of second metals (M=Mn,Fe,Co,Ni) and Pd. With 3?nitrostyrene as the model molecule and H2 as the hydrogen source, this study investigated the effect of second metals on the selective hydrogenation performance of Pd?based catalysts. The Pd?based catalysts were characterized and tested by methods including X?ray diffraction (XRD), transmission electron microscope (TEM),and gas chromatography.The results reveal that when pure Pd/C is used as the catalyst, the conversion reaches 100% for 1.5 h, but the selectivity of 3?nitrophenylethane is only 29%, and the selectivity of 3?aminophenylethane is 71%. After the introduction of second metals, the selectivity of 3?nitrophenylethane is increased to 75%~100% under the same conditions. Among them,PdFe/C has the best performance(100%) in the hydrogenation of 3?nitrostyrene to 3?nitrophenylethane, and high conversion(100%) and selectivity (99%) of 3?nitrophenylethane can still maintain after ten reaction cycles. It can effectively avoid over?hydrogenation and realize the selective hydrogenation of 3?nitrostyrene to 3?nitrophenylethane.

国家自然科学基金项目(22102078);山东省自然科学基金项目(ZR2021QB091)

10.3969/j.issn.1006-396X.2022.05.009