作　　者： ; ; ; ; ;

机构地区： 上海大学

出　　处： 《无机化学学报》 2003年第11期1202-1206,共5页

摘　　要： 以固定床催化苯酚羟基化制苯二酚为目标反应,制备了负载型TS-1/硅藻土催化剂。运用FT-IR、XRD、UV-Vis、ICP-AES和NH3-TPD等表征手段,研究了预处理介质对TS-1/硅藻土催化剂物化和催化性能的影响。研究表明,用KAc、NaAc、NH4Ac、NH4Cl和HNO3水溶液预处理催化剂后,对TS-1分子筛的骨架结构和骨架Ti的存在无明显影响,但可脱除部分非骨架TiO2,使催化剂的表面酸浓度有所下降,提高了苯酚羟基化反应的活性、选择性和H2O2的有效利用率。用碱性溶液(NH3·H2O、Na2CO3和Na3PO4)处理后,催化剂的表面酸强度和酸浓度有所增加,但TS-1分子筛的骨架结构由于硅元素被碱溶解而遭到破坏,从而使TS-1/硅藻土对苯酚羟基化反应的催化性能明显下降甚至失活。 The TS-1/diatomite catalyst was prepared for the hydroxylation of phenol with H2O2 in a fixed-bed reactor and the effect of pretreatment on the properties of TS-1/diatomite were studied with FT-IR, XRD, UV-Vis, ICP-AES and NH3-TPD techniques. It was shown that the framework structure of TS-1 pretreated with aqueous solutions of KAc, NaAc, NH4Ac, NH4Cl and HNO3 was not destroyed and titanium in the framework was not removed, but some extra-framework TiO2 could be removed partly, and the acid concentration on the surface of the TS-1/diatomite catalyst decreased slightly, which improves the activity, selectivity and utilization of H2O2 for hydroxylation of phenol. When the TS-1/diatomite catalyst was pretreated by bases solutions of NH3 (.) H2O, Na2CO3 and Na3PO4, the framework silicon was dissolved partly and the framework structure of TS-1 was destroyed, which leads to the slight increase of strength and concentration of acid sites on the surface of catalyst, and the decrease or loss of the framework titanium, and so that the catalytic activity of the TS-1/diatomite catalyst for hydroxylation of phenol descended or deactivated completely.

关 键 词： 预处理 硅藻土 催化剂 性能 苯酚 羟基化 固定床反应器

领　　域： [化学工程] [理学] [理学]