摘要
制备了用于固定床反应器的负载型TS 1分子筛催化剂 ,并以苯酚羟基化为探针反应 ,研究了载体、钛含量和预处理剂等对负载型TS 1分子筛催化性能的影响 ,考察了固定床反应器中苯酚羟基化反应的工艺条件 .结果表明 ,酸性较强的载体会加剧H2 O2 的分解 ,导致苯酚的转化率和H2 O2 的有效利用率下降 ;在所研究的ZSM 5 ,TiO2 ,Al2 O3 ,ZrO2 ,SiO2 和硅藻土载体中 ,硅藻土具有最好的催化性能 ;催化剂的活性与骨架钛含量有关 ;用HNO3 ,KAc ,NaAc,NH4Ac和NH4Cl处理过的催化剂 ,活性和选择性得到提高 ,而用NH3 ·H2 O ,Na2 CO3 和Na3 PO4等碱性物质处理后 ,催化剂的活性则下降 ;溶剂、反应温度、原料空速和苯酚 /H2 O2 摩尔比对苯酚羟基化反应有很大影响 .以丙酮为溶剂 ,在苯酚 /H2 O2 摩尔比为 3,反应温度为 84℃ ,WHSV为 8 4 6h-1的反应条件下 ,苯酚转化率、H2 O2 转化率、苯二酚选择性以及H2 O2 的有效利用率可分别达到 2 7 7% ,94 8% ,97 7%和 75 1% .
The TS 1 zeolite prepared by the hydrothermal method was supported on different supports, and their catalytic performance for the hydroxylation of phenol in a fixed bed reactor system was studied. The effects of the support property, Ti content and pretreatment reagent on the performance of the supported TS 1 catalyst were investigated. The stronger acid sites on the support promoted the decomposition of H 2O 2 and decreased the phenol conversion and utilization efficiency of H 2O 2. Among ZSM 5, TiO 2, Al 2O 3, ZrO 2, SiO 2 and diatomite supports, diatomite was the best support of TS 1 for the hydroxylation of phenol. The catalytic performance of the TS 1/diatomite catalyst for the hydroxylation was related to the amount of Ti in the TS 1 lattice and was improved by pretreatment with HNO 3, KAc, NaAc, NH 4Ac and NH 4Cl aqueous solutions. On the contrary, the activity of TS 1/diatomite was inhibited by pretreatment with base solutions such as NH 3·H 2O, Na 2CO 3 and Na 3PO 4. The studies of reaction conditions in the fixed bed reactor system showed that the operation parameters such as solvent, reaction temperature, WHSV and phenol/H 2O 2 ratio had obvious influences on the hydroxylation of phenol. When the reaction was carried out using acetone as the solvent with a phenol to H 2O 2 molar ratio of 3 at WHSV=8 46 h -1 and 84 ℃, the phenol conversion, H 2O 2 conversion, selectivity for dihydroxybenzene and utilization efficiency of H 2O 2 reached 27 7%, 94 8%, 97 7% and 75 1%, respectively.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2004年第1期49-54,共6页
关键词
TS—1
负载型催化剂
苯酚
过氧化氢
羟基化
苯二酚
固定床反应器
titanium silicalite 1, supported catalyst,phenol, hydrogen peroxide, hydroxylation,dihydroxybenzene, fixed bed reactor
