【摘要】 通过浸渍法制备氧化锆改性的氧化铝载体,并采用改进的阴离子交换法(DAE)制备了负载型纳米金催化剂。以分子氧为氧化剂,考察了金催化剂在环己烷选择性氧化制环己酮和环己醇反应中的催化性能。结果表明,提高锆含量,环己烷转化率保持稳定,环己酮和环己醇总选择性,尤其是环己酮的选择性明显提高。随着金负载量增加,金颗粒增大,催化剂的活性降低,金颗粒在6nm以下的催化剂具有很高的催化活性。在423K、1.5MPa、3h反应条件下,0.6%(wt)金和17%(wt)锆含量的催化剂上环己烷氧化得到9.5%的转化率,环己酮和环己醇的选择性分别为38.8%和51.5%。更多还原

【Abstract】 Nano gold catalysts supported on zirconia-modified alumina were prepared via the modified direct anionic exchange method(DAE),and the zirconia-modified alumina supports were prepared by wet impregnation method.The catalytic performances of the prepared catalysts for the catalytic oxidation of cyclohexane into cyclohexanone and cyclohexanol were investigated by using the oxygen as the oxidant.The results show that,increasing the zirconia content in the catalyst,its catalytic activity is well retained,and the selectivity of cyclohexanone and cyclohexanol,especially that of the cyclohexanone,can be remarkably enhanced.It was also found that,in the catalyst prepared,the lower the gold content,the smaller the size of the nano gold particles and the higher the catalytic activity the catalyst has.The prepared catalysts with nano gold particle sizes smaller than 6 nm exhibit relatively very high catalytic activity.Under the reaction conditions of 423 K,1.5 MPa and 3 h,using the gold catalyst supported on zirconia-modified alumina with 0.6%(wt) gold and 17%(wt) zirconia,the cyclohexane conversion ratio can reach 9.5% and the selectivity of cyclohexanone and cyclohexanol are 38.8% and 51.5%,respectively.更多还原