直接合成二甲醚的铜-锰催化剂

以Cu -Mn为主要活性组份 ,以锌、铬、钨、钼、铁、钴、镍等为助催化剂 ,采用共浸渍法 ,将铜、锰等直接负载在氧化铝上 ,获得了一种新型的负载型一步合成二甲醚催化剂。该催化剂具有制备工艺简单、强度高、稳定性好、易重复等特点。试验结果显示 :在负载的Cu -Mn催化剂上 ,CO加氢可以生成二甲醚 ,而且当n(Cu) /n(Mn) =1 /2时 ,CO的转化率和二甲醚的收率均佳 ;少量锌的添加有利于提高催化剂的活性和二甲醚的选择性 ;而铁、钴、镍的添加主要使CO发生甲烷化反应。

Direct Synthesis of Dimethyl Ether on Supported Cu-Mn Catalysts

A new catalyst system of Cu-Mn-M supported on γ-Al 2O 3 was developed for dimethyl ether(DME) synthesis via CO hydrogenation in a fixed-bed reactor The catalyst was prepared by directly co- impregnating the nitrate of Cu and Mn on γ-Al 2O 3,and then dried and calcined Promoters such as Zn,Cr,W,Mo,Fe,Co,Ni were used and tested Results show that the catalyst has the highest reactivity of CO and a high DME selectivity when n (Mn)/ n (Cu)=2/1 The addition of a small amount of Zn can increase the selectivity of DME The best DME yield reaches 46 0%(at 63 5% conversion of CO) under 2 0 MPa,275 ℃ and 1500 h -1 on Cu 1 2 -Mn 2 4 -Zn/γ-Al 2O 3 catalyst which is higher than the hybrid catalyst consisting of a methanol synthesis catalyst and a dehydration catalyst At the same time,the catalysts have high stability and good mechanical properties,and are easily repeatable However,the main product of CO hydrogenation was CH 4 on addition of Fe,Co or Ni on Cu 1 2 -Mn 2 4 -Zn/γ-Al 2O 3