(T_(p-Cl)PPFe)_2O/Co(OAc)_2催化对二甲苯空气氧化反应及条件优化

Aerobic oxidation of p-xylene catalyzed by (T_(p-Cl)PPFe)_2O/Co(OAc)_2 in absence of solvent and process optimization

对二甲苯液相氧化是目前石油化工领域最重要的碳氢化合物氧化反应之一,本文报道了μ-氧双[四对氯苯基卟吩]合铁/醋酸钴[(Tp-ClPPFe)2O/Co(OAc)2]复合催化体系在无溶剂体系中催化空气氧化对二甲苯的反应,初步考察了(Tp-ClPPFe)2O/Co(OAc)2复合催化体系的催化过程,在单因素考察催化剂种类和使用量对反应转化率和产物选择性影响的基础上,使用正交实验全面考察了该反应中时间、温度、压力、空气流速、金属卟啉用量、醋酸钴/金属卟啉质量比对反应转化率和产物选择性的影响,获得了优化反应条件。通过实验对优化条件进行了确认。实验表明,在上述优化条件下,对二甲苯转化率达65.0%,对甲基苯甲酸和对苯二甲酸选择性分别为81.0%和13.0%。

Liquid-phase oxidation of p-xylene is one of the most significant reactions in the petrochemical industry. The aerobic oxidation of p-xylene catalyzed by μ-oxo his [tetra-para-chlorophenylporphinato] iron and cobalt acetate [ （T-ClPPFe）2O/Co（OAc）2] without solvent and bromides was reported, and the co-catalysis between （Tp-ClPPFe）2Oand Co（OAc）2 was proposed. The influence of reaction time, reaction temperature, pressure, air flow rate, the amount of porphyrins and the mass ratio of Co （OAc）2/ （Tp-ClPPFe）2O on the p-xylene aerobic oxidation was studied. The optimized conditions oxidation with air were obtained by using orthogonal design and confirmed by critical optimized conditions of the amount of porphyrins 17.5 mg, the ratio of Co（OAc）2/ （T pressure 0.8 MPa, temperature 180℃, reaction time 4.5 h and air flow rate 0.20 m^3 · h^-1 the conversion of p-xylene was 65.0%, the selectivity of p-toluic acid and terephthalic acid were 81. 0% and 13.0% respectively.