络合剂对硫醇催化剂性能的影响

Effect of complexant on the performance of catalysts for thiol production

以硝酸钴和七钼酸铵为原料配制钴-钼浸渍液,将酒石酸、柠檬酸和乙二胺四乙酸按照比例添加到浸渍液中,再浸渍到含介孔硅的载体上制备系列催化剂。通过孔结构、HRTEM、H_(2)-TPR和NH_(3)-TPD等对其进行表征,表明添加络合剂可以降低活性金属与载体间的作用力,更有利于形成高活性Ⅱ类活性相,且片晶长度更长,片晶层数更多,同时又具有较大的比表面积和孔容,酸量及中强酸也得到增加。因此,添加络合剂的催化剂具有更高的转化率和硫醇选择性。

A cobalt molybdenum impregnation solution was prepared using cobalt nitrate and ammonium heptamolybdate as raw materials.Tartaric acid(TA),citric acid(CA),and ethylenediamine tetraacetic acid(EDTA)were added to the impregnation solution and impregnated onto a carrier containing mesoporous silicon to prepare a series of catalysts.By characterization of N_(2) adsorption-desorption,HRTEM,H_(2)-TPR,NH_(3)-TPD,etc.,it was found that the addition of a complexing agent reduced the interaction force between the active metal and the carrier,which was conducive to the formation of more ClassⅡactive phases,with longer crystal length and more crystal layers.At the same time,it has a larger specific surface area and pore volume,and the acidity and medium strength of the acid are also increased.Therefore,catalysts with added complexing agents have higher conversion and thiol selectivity.