双功能催化剂Ni_(x)/Mg_(y)Al_(2)O _(y+3)用于丁酮烷基化反应

Bifunctional Catalysts Ni_(x)/Mg_(y)Al_(2)O _(y+3) for Alkylation of Butanone

以Nix/zMgy/zAl2/z(OH)2(CO3)1/z(z=x+y+2,x=0.2、1,5≤y≤11.8)水滑石为前驱体,经高温焙烧和H2还原后得到了一系列可用于甲醇-丁酮(MEK)烷基化反应的Nix/MgyAl2Oy+3(x=0.2、1,5≤y≤11.8)双功能催化剂,并采用X射线衍射(XRD)、透射电子显微镜(TEM)、程序升温还原(TPR)、程序升温脱附(TPD)等技术对催化剂的结构和形貌进行了表征。活性实验结果发现Ni/Mg9Al2O12催化剂具有较好的活性,在常压、温度280℃、原料液时空速(LHSV)6.0 h-1的条件下,丁酮的转化率为61.6%,3‑戊酮(DEK)和3‑甲基‑2‑丁酮(MIPK)的选择性分别为45.0%和17.7%。表征结果表明催化剂中合适的活性金属Ni和MgO含量对提高DEK和MIPK的选择性具有重要的影响,Ni与催化剂表面碱量之间的协同作用可能是影响催化剂的活性和选择性的主要因素。

A series of Nix/MgyAl2Oy+3(x=0.2 or 1,5≤y≤11.8)bifunctional catalysts were prepared by calcination and hydrogen reduction of Nix/zMgy/zAl2/z(OH)2(CO3)1/z(z=x+y+2,x=0.2 or 1,5≤y≤11.8)hydrotalcite precursors.The structure and morphology of these catalysts were characterized via X‑ray diffraction(XRD),transmission electron microscope(TEM),temperature program reduction(TPR),temperature program desorption(TPD)and other technologies.It was found that Ni/Mg9Al2O12 exhibited excellent activity for the alkylation of butanone(MEK)with methanol.The conversion of butanone reached 61.6%,with the 45.0%and 17.7%selectivity of 3‑pentanone(DEK)and 3‑methyl‑2‑butanone(MIPK)under atmospheric pressure,280℃,and liquid hourly space velocity(LHSV)of 6.0 h-1.The characterization results show that the appropriate active metal Ni and MgO contents in the catalyst play an important role on the selectivity of DEK and MIPK.The synergistic effect between Ni and the surface alkalinity may be the main factor affecting the activity and selectivity of the catalyst.