Fe-Mo-Ni催化剂的制备及其催化选择氧化制对苯二甲醛  

The Preparation of Fe-Mo-Ni Catalyst and Synthesis of Terephthalaldehyde through Selective Catalytic Oxidation

作　　者：刘自力[1,2] 刘艳冰[2] 李辉[2] 陈胜洲[1] 

机构地区：[1]广州大学化学化工学院,广东广州510006 [2]广西大学化学化工学院,广西南宁530004

出　　处：《高校化学工程学报》2010年第2期221-225,共5页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金资助课题(20776031);广州大学科研创新团队项目(广大[2008]127号)

摘　　要：采用溶胶-凝胶法制备了Fe-Mo-Ni三元结构催化剂,以对二甲苯选择氧化为对苯二甲醛(TPAL)为探针反应,研究了该催化剂的制备条件及其催化反应特征,并用热分析(TG-DSC)、X射线衍射(XRD)和紫外漫反射(DRS)对该催化剂进行了分析表征。研究表明,助剂Ni提高了Fe-Mo催化剂的催化活性,使对苯二甲醛的收率由改性前的24.8%提高到38.3%,并且能显著提高催化剂的活性稳定性;影响Fe-Mo-Ni三元结构催化剂的主要因素是Ni的添加量和催化剂焙烧温度,其中Ni的适宜添加量为5%(mol),适宜的焙烧温度为500℃。影响其催化反应的主要因素是空气与对二甲苯流速比和空速,适宜的流速比为150000,适宜的空速为25h-1(对二甲苯流量恒定在0.01mL?min?1):在上述优化的条件下,对二甲苯的转化率为80.3%、对苯二甲醛的选择性为47.7%、对苯二甲醛收率为38.3%。掺入的Ni助剂高度分散在催化剂表面,并参与Mo物种活性中心的形成,使Mo物种的配位和价态发生变化。Fe-Mo-Ni catalyst was prepared via sol-gel method and was characterized by TG-DSC, XRD and DRS. The catalytic activity of the prepared Fe-Mo-Ni catalyst was examined by the probe reaction of selectively oxidizing p-xylene to terephthalaldehyde （TPAL）. The results show that, comparing with catalyst Fe-Mo, using catalyst Fe-Mo-Ni, the yield of TPAL increases from 24.8% to 38.3% and doping Ni in the catalyst can improve the activity stability of the catalyst. The main influence factors of the Fe-Mo-Ni catalyst activity are the doping amount of Ni and the calcination temperature of the catalyst; the optimum doping amount of Ni found is 5%（mol） and the found optimum calcination temperature is 500℃. The main factors affecting the results of the catalytic selective oxidation reaction are the flow rate ratio of air to p-xylene and the space velocity; the optimal flow rate ratio found is 150000 （the flow rate of p-xylene is maintained at 0.01 mL？min？1） and the found optimal space velocity is 25 h-1. Under above optimal conditions, the conversion ratio of p-xylene reaches 80.3%, the selectivity and the yield of TPAL reach 47.7% and 38.3%, respectively. The promoter Ni added disperses highly on the catalyst surface and could change the coordination and the valence state of Mo via participating in the formation of Mo species active centre.

关 键 词：Fe-Mo-Ni催化剂 对二甲苯 对苯二甲醛 选择性氧化 

分 类 号：TQ426.6[化学工程] TQ426.83