高分子负载铁催化剂的制备及其甲苯选择性氯化反应性能

2015年8月第23卷第8期 工业催化INDUSTRIAL CATALYSIS AUg.2015Vol.23 No.8催化剂制备与研究

收稿日期:2015-03-20 基金项目:江苏省产学研联合创新资金-前瞻性联合研究项目(SBY201320102)作者简介:葛裕华,1966生,男,江苏省高邮市人,博士,副教授,主要从事有机合成和工业催化的研究。

通讯联系人:葛裕华。高分子负载铁催化剂的制备及其

甲苯选择性氯化反应性能

王跃华,李婷婷,任开路,葛裕华*

(东南大学化学化工学院,江苏南京211189)

摘 要:通过金属铁离子与高分子载体进行螯合反应,制备高分子负载铁催化剂,用原子吸收光谱法测定催化剂中Fe 3﹢含量,并利用傅里叶变换红外光谱仪、扫描电子显微镜、热重分析对制备的催化剂分子结构、微球形貌和热稳定性进行表征,并研究有机硫助催化剂的添加对高分子负载铁催化剂催化甲苯选择性氯化性能的影响。结果表明,铁离子与乙酰丙酮基的两个氧原子形成了六元螯

合环的强相互作用,使Cl 2分子更易极化,

提高了催化反应速率;有机硫助催化剂不仅改变Cl —Cl 键的强度,而且增大了亲电试剂的空间位阻,从而显著提高对位选择性和稳定性。1%(占甲苯的质量分数)高分子负载铁催化剂/0.05%(占甲苯的质量分数)有机硫助催化剂催化甲苯选择性氯

化反应表现出最佳的催化性能,氯化反应2h ,甲苯转化率超过90%,对氯甲苯选择性55.74%,多氯甲苯质量分数低于1%。催化剂可重复使用。

关键词:催化化学;高分子;螯合反应;负载催化剂;选择性氯化;回收利用

doi :10.3969/j.issn.1008-1143.2015.08.005

中图分类号:O643.26;TQ426.6 文献标识码:A 文章编号:1008-1143(2015)08-0609-05Preparation and application of a polymer-supported iron catalyst for selective chlorination of toluene

Wang Yuehua ,Li tingting ,Ren Kailu ,Ge Yuhua *

(School of Chemistry and Chemical Engineering ,SoUtheast University ,Nanjing 211189,JiangsU ,China )Abstract :A polymer-sUpported iron catalyst (YCH 2CHAcAc-Fe 3﹢)was prepared by chelation reaction of Fe 3﹢and polymer sUpport.The molecUlar strUctUre ,microsphere morphology and thermal stability of the as-prepared catalyst was characterized by foUrier transform infrared spectrometer ,scanning electron micro-scope and thermogravimetric analysis ,and its iron content was determined by atomic absorption spectrom-etry.The effects of sUlfUr-containing cocatalyst (OS )on the catalytic properties of polymer-sUpported iron catalyst (YCH 2CHAcAc-Fe 3﹢)for the selective chlorination of tolUene were investigated.The resUlts showed that iron ions formed a chelated six-member ring with two oxygen atoms of acetylacetone ,and Cl 2molecUles were easier to be polarized dUe to the strong interaction between iron ions and oxygen atoms ,so

the chlorination rates was improved ;sUlfUr-containing cocatalyst (OS )not only changed the bond strength

of Cl —Cl ,bUt also increased the steric hindrance of electrophilic reagent ,which greatly improved the catalytic selectivity and stability.YCH 2CHAcAc-Fe 3﹢catalyst (1%of tolUene mass )with sUlfUr-containing cocatalyst (0.05%of tolUene mass )exhibited the best catalytic performance Under the condition of room

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