NHPI/SMA-Co催化氧气氧化环己烷的工艺研究

Study on Oxidation of Cyclohexane Catalyzed by Oxygen over NHPI/SMA-Co

以聚苯乙烯马来酸酐共聚物（SMA）及六水合硝酸钴为原料，制备了苯乙烯．马来酸酐钴盐（SMA-Co），利用FTIR、元素分析、UV-vis、SEM、EDS、XRD、TG对催化剂结构与性能进行了表征与测试。将N-羟基邻苯二甲酰亚胺（NHPI）与SMA-Co组成复合催化体系，考察了NHPI与SMA-CO物质的量比、催化剂用量、反应温度、氧气压力、反应时间对NHPI／SMA-Co催化氧气氧化环己烷反应的影响。结果表明：当环己烷为5mL、乙腈为10mL、n（NHPI）：n（SMA-Co）=10：3、NHPI／SMA-Co用量0．04g、反应温度120℃，初始氧气压力为1．0MPa、反应6h时，环己烷转化率最大，为19．84％，环己醇选择性为22．23％，环己酮选择性为38．65％，环己酮和环己醇（KA油）总选择性达60．88％。催化剂经过4次回收利用后，催化剂活性无明显降低。

Styrene-maleic anhydride copolymer cobalt salt （SMA-Co） was prepared using styrene-maleic anhydride copolymer （SMA） and cobalt nitrate hexahydrate as raw materials. The sample was characterized by FTIR, elemental analysis, UV-vis, SEM, EDS, XRD and TG. Subsequently, a composite catalytic system composed of N-hydroxyphthalmide （NHPI） and SMA-Co for the oxidation of cyclohexane was constructed. The effects of molar ratio of NHPI to SMA-Co, catalyst dosage, reaction temperature, oxygen pressure, reaction time on the oxidation of cyclohexane were investigated. The optimized reaction conditions were obtained as follows： 5 mL cyclohexane, 10 mL acetonitrile, n（NHFI） ： n（SMA-Co）=10 ： 3,NHPI/SMA-Co dosage 0.04 g, reaction temperature 120 ℃, initial oxygen pressure 1.0 MPa, reaction time 6 h. Under these conditions, the conversion of cyclohexane was 19.84%, and the selectivities of cyclohexanol and cyclohexanone were 22.23% and 38.65%, respectively. The selectivity of KA oil （the mixture of cyclohexanone and cyclohexanol） Was 60.88%. The catalytic activity of the catalyst was not obviously reduced after being recycled four times, indicating that the catalyst could be recycled,