铜盐改性HKZ-1分子筛的制备及其催化苯酚羟基化研究

水热法合成KZ-1分子筛,并将其与饱和NH4Cl溶液离子交换得到H型KZ-1分子筛(HKZ-1)。将HKZ-1分子筛分别与不同浓度的铜氨络合物溶液离子交换得到铜含量分别为0.18%和5.79%的催化剂,而采用浸渍法可以得到铜含量为6%的催化剂。采用扫描电镜、X射线衍射、H2程序升温还原、原子吸收等表征手段对所合成系列催化剂进行表征。结果表明,HKZ-1分子筛大小均一且结晶度良好,改性后的分子筛骨架结构基本没有发生改变。以苯酚羟基化为探针反应考察分子筛催化活性,结果表明,铜含量为0.18%的分子筛具有较好的催化活性,其催化苯酚羟基化的转化率可以达到36%,对苯二酚选择性可以达到100%,并且具有回收利用的价值。

Preparation of Copper Modified HKZ-1 Zeolites and Research on Catalytic Phenol Hydroxylation

KZ-1zeolite was prepared by hydrothermal method and ion exchanged with saturated NH4 Cl solution to obtain HKZ-1zeolites.HKZ-1zeolites were further ion exchanged with different concentrations of copper ammonia complex solution.The catalysts were obtained with different copper content of 0.18% and 5.79%,respectively.Almost the same procedure was adopted to get impregnated catalyst with copper content of 6%.All obtained zeolites were characterized by SEM,XRD,H2-TPR and AAS etc.The results displayed that HKZ-1zeolites were very uniform with high crystallites and the skeleton structure of modified zeolites remained integrate.The zeolites were investigated with the catalytic hydroxylation of phenol.The results showed that the zeolite with copper content of0.18% showed the highest activity（36%）,that the conversion rate of catalytic hydroxylation of phenol could reach 36% and the selectivity of hydroquinone could be 100%.Moreover,the catalyst could be effectively reused.