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

 采用TiCl4气固相同晶取代法制得的Ti－ZSM－5作催化剂，对H2O2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H2O2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H2O2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（H2O2）＝7．91，催化剂用量为20g／L，反应温度为343K的条件下，反应360min时，苯乙醛选择性和H2O2利用率分别可达91．9％和88．6％．

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

The macro-kinetics of styrene oxidation catalyzed by Ti-ZSM-5 prepared throug h TiCl4 gas-solid isomorphous substitution, using 30%H2O2 as oxidant, was studied. The effects of catalyst amount, styrene and H2O2 concentration on the reaction rate of styrene oxidation were also investigated in details. Th e results showed that the reaction rate of styrene oxidation was first order wit h respect to both Ti-ZSM-5 amount and styrene concentration, and was 1/2 order for H2O2 concentration. The apparent activation energy Ea of 48.14 k J/mol was obtained according to temperature effect on the kinetics of styrene ox idation. At the same time, phenylacetaldehyde selectivity and H2O2 effective utilization ratio can reach 91.9% and 88.6% respectively, under the condition s of n(PhCH∶CH2)/n(H2O2)=7.91, ［Ti -ZSM-5］= 20 g/L, T=343 K and t=360 min.