钴/硅藻土催化肉桂醛选择加氢制肉桂醇

对肉桂醛选择加氢制肉桂醇的钴/硅藻土催化剂进行了研究。考察了不同载体钴催化剂的活性及钴负载量、焙烧温度、还原温度对钴/硅藻土催化剂活性的影响。实验结果表明,酸性载体比碱性载体好,在酸性载体中硅藻土具有更好的助催化作用;在钴负载量(质量分数,下同)9%的钴/硅藻土催化剂和硅藻土载体上,肉桂醛的转化率分别为52.7%和30.6%,肉桂醇的选择性分别为82.8%和29.8%;钴/硅藻土催化剂的最佳钴负载量为12%、最佳焙烧温度为673K、最佳还原温度为723K。钴/硅藻土催化剂存在诱导期,诱导期为8h;反应8h时后,催化剂的活性和选择性均趋于平稳,肉桂醛转化率和肉桂醇选择性分别为72%和80%左右,13h内催化剂活性没有下降。

Selective Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol over Co/Diatomite Catalysts

Performance of Co/diatomite catalyst in selective hydrogenation of cinnamaldehyde to cinnamyl alcohol was studied.Effects of different supports,cobalt loading amount,calcination temperature and reduction temperature on catalytic activity were investigated.Basic support is less promising in comparing with acidic support and diatomite is preferable as support in selective hydrogenation.Conversion of cinnamaldehyde and selectivity to cinnamyl alcohol are 52.7% and 82.8% over Co/diatomite(Co mass fraction 9%).Optimal preparation conditions are cobalt 12%(mass fraction),calcination temperature 673 K and reduction temperature 723 K.There is an induction period of 8 h for selective hydrogenation over Co/diatomite catalyst.Conversion of cinnamaldehyde and selectivity to cinnamyl alcohol can reach 72% and 80% respectively after reaction for 8 h,and can keep steady for at least 13 h.