催化剂制备与研究 预处理对钯炭催化剂及其在肉桂醛加氢中性能的影响

采用不同预处理方式对活性炭表面进行改性,并制备钯炭催化剂。对活性炭的比表面积、孔结构等物理性质和含氧官能团种类以及钯炭催化剂进行表征,探究预处理对活性炭表面物化性能产生的变化和对钯炭催化剂在肉桂醛加氢反应中催化活性的影响。结果表明,氧化预处理使活性炭的比表面积和孔容下降,使钯炭催化剂上的钯粒子尺寸相对更小;碱预处理有一定的扩孔作用,使钯炭催化剂上的钯粒子尺寸更大。在肉桂醛加氢反应中,钯粒子尺寸越小的催化剂催化活性更高,而钯粒子尺寸更大的催化剂上肉桂醇选择性更高。

Effect of pretreatments on palladium carbon catalyst and its performance for hydrogenation of cinnamaldehyde

The surface of activated carbon was modified by different pretreatment methods,and palladium supported activated carbon catalysts were prepared.The physical properties and the type of oxygen-containing functional groups of activated carbon and Pd/C catalyst were characterized by BET,FT-IR,XRD and TEM.The effects of the pretreatment on the physicochemical properties of the activated carbon and Pd/C catalyst for hydrogenation of cinnamaldehyde were investigated.The results showed that the specific surface area and pore volume of the activated carbon by oxidative pretreatment decreased,and the palladium particles of Pd/C catalyst were relatively small.The alkali treatment had a certain effect of enlarging pore, and Pd/C catalyst had larger Pd particles.In the hydrogenation reaction of cinnamaldehyde,the smaller the particle size of palladium was,the higher the catalytic activity of the catalyst was,and the catalyst with larger Pd particle size possessed higher selectivity to cinnamyl alcohol.