气固相法合成的Ti-ZSM-5催化剂上苯乙烯氧化反应的宏观动力学

Kinetics of Styrene Oxidation Catalyzed by Ti-ZSM-5 Prepared through Gas-Solid Isomorphous Substitution

采用TiCl4 气固相同晶取代法制得的Ti ZSM 5作催化剂 ,对H2 O2 氧化苯乙烯反应的宏观动力学进行了研究 ,考察了催化剂、苯乙烯和H2 O2 用量及反应温度对苯乙烯氧化反应速率的影响 .结果表明 ,催化剂Ti ZSM 5和底物苯乙烯对苯乙烯氧化反应速率的贡献均为一级 ,而H2 O2 为 1/ 2级 ;苯乙烯氧化反应的表观活化能Ea=48 14kJ/mol.当以丙酮为溶剂 ,在n(PhCH∶CH2 ) /n(H2 O2 ) =7 91,催化剂用量为 2 0 g/L ,反应温度为 343K的条件下 ,反应 36 0min时 ,苯乙醛选择性和H2 O2 利用率分别可达 91 9%和 88 6 % .

The macro kinetics of styrene oxidation catalyzed by Ti ZSM 5 prepared through TiCl 4 gas solid isomorphous substitution, using 30%H 2O 2 as oxidant, was studied. The effects of catalyst amount, styrene and H 2O 2 concentration on the reaction rate of styrene oxidation were also investigated in details. The results showed that the reaction rate of styrene oxidation was first order with respect to both Ti ZSM 5 amount and styrene concentration, and was 1/2 order for H 2O 2 concentration. The apparent activation energy E a of 48 14 kJ/mol was obtained according to temperature effect on the kinetics of styrene oxidation. At the same time, phenylacetaldehyde selectivity and H 2O 2 effective utilization ratio can reach 91 9% and 88 6% respectively, under the conditions of n (PhCH∶CH 2)/ n (H 2O 2)=7 91, [Ti ZSM 5]= 20 g/L, T =343 K and t =360 min.