锆掺杂TiO_2光催化降解2-CEES和DMMP的原位红外与固体核磁研究  

In-situ FTIR and SSNMR Study of Photocatalytic Degradation of 2-CEES and DMMP on Zirconium-doped TiO_2

作　　者：沈忠[1,2] 钟近艺[1,3] 王泠沄 郑永超[1] 崔燕[1,3] 陈立坤[1] 

机构地区：[1]防化研究院,北京102205 [2]西北核技术研究所,陕西西安710024 [3]国民核生化灾害防护国家重点实验室,北京102205

出　　处：《分子催化》2016年第3期260-268,共9页Journal of Molecular Catalysis(China)

基　　金：国家自然科学基金资助项目(21207160)~~

摘　　要：在国内率先将金属离子掺杂型纳米TiO_2用于化学毒剂(CWAs)洗消领域,制备了系列浓度的锆掺杂纳米TiO_2(Zr-TiO_2).为了从分子水平上认识Zr-TiO_2对CWAs的消毒机制,结合原位红外(in-situ FTIR)与固体核磁共振(SSNMR)技术,研究了掺杂前后样品表面2-CEES和DMMP的反应机理和动力学变化.结果显示:制备样品中无尿素残留,且掺杂浓度为10.05%的Zr-TiO_2光催化活性最佳;与掺杂前相比,该样品对2-CEES和DMMP的光催化降解速率加快,但反应机制不变:对DMMP的降解主要通过同时发生P-OCH3氧化和P-CH3分解,对2-CEES则依次通过C—Cl键断裂、C—S键断裂和S原子氧化完成降解,两种模拟剂在反应过程中均未生成有毒中间产物.通过研究,建立了适用于化学毒剂洗消领域的原位在线分析方法,掌握了模拟剂的光催化消毒反应机理、产物与动力学规律,为今后实毒样品的测试打下了基础.Zirconium-doped anatase TiO_2 photocatalyst with high disinfection activity to Chemical Warfare Agents（ CWAs） were prepared by homogeneous precipitation method. To gain further insights in the fundamental properties of the material for 2-CEES and DMMP photocatalytic degradation,in-situ fourier transform infrared spectroscopy（ in-situ FTIR） and solid-state nuclear magnetic resonance（ SSNMR） were used for revealing detailed information on reaction mechanism of molecular transformations occurring on the nanoparticles upon photon irradiation and kinetics of photocatalytic disinfection. The results show that no urea residue was detected in the sample. The Zr（ 10.05%）-TiO_2 exhibits the best photocatalytic performance. Compared with the undoped TiO_2,Zr（ 10. 05%）-TiO_2 had higher photocatalytic degradation rates of 2-CEES and DMMP,while the reaction mechanism of disinfection was unchanged. Mainly through the oxidation of P-OCH3 and decomposition of P-CH3,DMMP was completely degraded,and these two processes were simultaneous. 2-CEES was completely degraded followed by the breaking of C—Cl,C—S,and the oxidation of S atoms. The two simulants did not generate toxic intermediates in the reaction process. In this study,the in-situ analytical methods for the field of CWAs decontamination were established,as well as the photocatalytic degradation mechanism,products,and reaction kinetics of simulants on the samples were comprehended. All of these have laid the foundation for the detection of CWAs in the future.

关 键 词：化学毒剂 洗消 二氧化钛 原位漫反射红外 固体核磁共振 

分 类 号：O643.32[理学—物理化学]