用于一步法合成丙基环己基环己酮的Pd/C催化剂

分别采用甲醛还原法和氢气还原法制备了5%Pd/C催化剂(Pd质量分数为5%)。采用X射线衍射、透射电子显微镜、H2化学吸附技术,研究了制备条件(pH、还原温度、前体种类)对5%Pd/C催化剂性能的影响,评价了5%Pd/C催化剂对丙基环己基苯酚一步加氢合成丙基环己基环己酮反应的催化性能,考察了添加K,Sn助剂对5%Pd/C催化剂性能的影响。实验结果表明,氢气还原法得到的Pd/C催化剂分散度高、活性好;K,Sn助剂能明显提高5%Pd/C催化剂的活性和丙基环己基环己酮的选择性,适宜的Sn质量分数为1.5%、K质量分数为10.0%。采用氢气还原法制备的5%Pd-1.5%Sn-10.0%K/C催化剂,以甲苯为溶剂,在反应温度423K、氢气压力0.5M Pa的条件下,丙基环己基环己酮的选择性可达89.1%,丙基环己基苯酚的转化率可达93.1%。

Pd/C Catalyst for Synthesis of 4-(4-Propylcyclohexyl)Cyclohexanone by One Step Method

Pd/C catalysts were prepared by formaldehyde-reduction and H2-reduction methods.Effects of preparation conditions,namely pH,reduction temperature and catalyst precursors,on properties of Pd/C catalyst were studied by means of XRD,TEM and H2-chemisorption.Influences of K and Sn promoters on Pd/C catalytic performance in 4-(4-alkylcyclohexyl)phenol selective hydrogenation were investigated.Pd/C catalyst prepared by hydrogen reduction method showed better Pd dispersion and higher catalytic activity than that prepared by formaldehyde reduction method.Addition of K and Sn promoters can improve selectivity of catalyst to 4-(4-proplycyclohexyl)cyclohexanone and 4-(4-proplycyclohexyl)phenol conversion.Under optimal conditions:K mass fraction 10.0%,Sn mass fraction 1.5%,hydrogen pressure 0.5MPa,423K and toluene as solvent,conversion of 4-(4-alkylcyclohexyl)phenol and selectivity to 4-(4-propylcyclohexyl)cyclohexanone can reach 93.1% and 89.1%,respectively.