新型固定床Raney镍(Ⅰ)成型合金的组成与焙烧条件

Novel fixed-bed Raney nickel catalysts(Ⅰ) Compositions and calcination conditions of alloy extrudates

以拟薄水铝石为黏结剂,将镍铝合金粉末成型,经高温焙烧、碱液浸取活化,制备出可应用于不饱和化合物固定床加氢的新型颗粒状Raney镍催化剂.采用TG-DTA、XRD、BET、SEM等方法和苯加氢模型反应,研究了成型合金焙烧条件以及拟薄水铝石加入量对催化剂性质与加氢活性的影响.实验结果表明,拟薄水铝石加入量以20%左右为宜;成型合金在860 ℃焙烧1～2 h,可获得适当的α-Al2O3生成量、较高的机械强度和较高的苯加氢活性.SEM和BET分析结果表明催化剂具有丰富的孔道结构.

A novel activated fixed-bed Raney nickel catalyst for hydrogenation of unsaturated organic compounds was prepared by extruding the Ni-A1 alloy powder with pseudoboehmite as binding material, calcining the extrudates in air at a high temperature and leaching out the aluminum with caustic solution. The effects of binding material contents and calcination conditions （calcination temperature and calcination time） on catalyst properties and catalytic activity were studied with TG-DTA, XRD, BET, SEM analyses and model reaction of benzene hydrogenation. The experimental results showed that the recommended pseudo-boehmite contents was 20%, and that the novel fixed-bed Raney nickel catalyst might acquire lower resultant α-Al2O3 content, higher particle compressive strength and higher benzene hydrogenation activity by calcining the alloy extrudates at 860 ℃ for 1--2 h in air. SEM and BET resuhs showed that the catalysts possessed abundant porous structures.