对二甲苯液相氨氧化制对甲基苯甲腈

Liquid Phase Ammoxidation of p-Xylene to p-Tolunitrile

以苯甲酸钴为催化剂、溴化铵为助催化剂,对对二甲苯常压液相氨氧化反应一步制备对甲基苯甲腈进行了研究;考察了反应时间、反应温度、助催化剂与催化剂配比、氨气与氧气配比、溶剂N,N-二甲基甲酰胺(DMF)与对二甲苯配比对反应的影响。实验结果表明,在反应温度409K、n(溴化铵)∶n(苯甲酸钴)=0.95、n(DMF)∶n(对二甲苯)=0.200、n(氨气)∶n(氧气)=0.037、反应时间2.0h的适宜条件下,对二甲苯转化率为85.0%(摩尔分数),对甲基苯甲腈的选择性和收率分别为65.0%(摩尔分数)和55.1%(摩尔分数)。

Liquid phase ammoxidation of p-xylene to p-tolunitrile on prepared cobalt benzoate catalyst and ammonium bromide co-catalyst was investigated. Effects of reaction temperature, reaction time, mole ratio of cobalt benzoate to ammonium bromide, mole ratio of NH3 to O2 and mole ratio of N,N-dimethylformamide （ DMF ） to p-xylene on ammoxidation were studied. Under optimal reaction conditions： temperature 409 K, mole ratio of cobalt benzoate to ammonium bromide 0.95, mole ratio of DMF to p-xylene 0.200,mole ratio of NH3 to O2 0.037 and reaction time 2.0 h, conversion of p-xylene, selectivity to p-tolunitrile and yield of p-tolunitrile can reach 85.0% （ mole fraction ）, 65.0% （ mole fraction） and 55.1% （ mole fraction）, respectively.