(NH_4)_(15)[Ce(PMo_9V_2O_(39))_2]·5H_2O杂多配合物合成及在苯酚羟化反应中的催化活性

The Synthesis and Catalytic Activity in Phenol Hydroxylation of (NH_4)_(15)[Ce(PMo_9V_2O_(39))_2]·5H_2O Heteropoly Compound

合成了 ( NH4) 1 5[Ce( PMo9V2 O39) 2 ]· 5 H2 O杂多化合物 ,并用 ICP,IR,UV,XRD等手段对其结构进行表征 ,结果表明该化合物是具有 Keggin结构的杂多化合物。考察了该杂多化合物对苯酚过氧化氢羟化反应的催化活性 ,研究了反应介质、反应温度、反应时间、反应体系 p H及 mol Ph OH∶ mol H2 O2 对催化活性的影响。实验结果表明 :以甲醇为溶剂 ,用标题化合物作催化剂 ,当 mol Ph OH∶ mol H2 O2 =2∶ 5 ,反应体系 p H为 5左右 ,反应温度 70℃ ,反应时间 4h时 ,苯酚转化率为 43.30 % ,对苯二酚产率可达 42 .2 0 %。

NH_4)_15[Ce(PMo_9_2O_39)_2]·5H_2O heteropoly compound was synthesized and characterized by ICP,IR,UV and XRD. The results showed that the compound was the Keggin structure. The catalytic activity of the heteropoly compounds is inverstigated in homogeneous phenol hydroxylation and the effects of reaction temperature, time, solvent and phenol∶H_2O_2(molar ratio) on the catalytic activity was tested. The experiment results showed that the conversion of phenol was 43.30% and the yield of hydroquione was 42.20% using methanol as solvent under the optimun reaction condition as follows: PhOH=0.50g,catalyst=50mg, phenol:H_2O_2(molar ratio)=1∶2.5, at 70℃, pH=5 and reaction time=4h.