非均相多钼氧簇/活性炭催化碘离子氧化性能研究  

Studies on Iodide Oxidation Catalyzed by Heterogeneous Molybdenum Oxide Clusters/Activated Carbon

作　　者：郭军 蔡丽丽[2] 解田[1] 周维珍 杨三可 谢泉[3] 刘其斌 秦军[3] Guo Jun;Cai Lili;Xie Tian;Zhou Weizhen;Yang Sanke;Xie Quan;Liu Qibin;Qin Jun(Postdoctoral Research Department Workstation,State Key Laboratory for Efficient Utilization of Medium and Low Grade Phosphate Rock and Its Associated Resources Wengfu(Group)Company Limited,Guizhou 550014,China;College of Chemistry and Materials Science,Guizhou Normal University,Guiyang,Guizhou 550001,China;Key Laboratory of Karst Environment and Geological Hazards,Postdoctoral Mobile Station of Electronic Science,Guizhou University,Guigyang,Guizhou 550025,China)

机构地区：[1]瓮福(集团)有限责任公司博士后科研工作站,中低品位磷矿及其共伴生资源高效利用国家重点实验室,贵州贵阳550014 [2]贵州师范大学化学与材料科学学院,贵州贵阳550001 [3]贵州大学国土资源部喀斯特环境与地质灾害重点实验室,电子科学与技术博士后流动站,贵州贵阳550025

出　　处：《化学世界》2020年第10期673-682,共10页Chemical World

基　　金：国家自然科学基金(No.21862005);贵州师范大学研究生创新基金(No.YC[2018]041);贵州省科技厅计划(Nos.黔科合LH字[2017]7336,黔科合基础[2019]1457,黔科合支撑[2019]2835,黔科合平台人才[2018]5769);贵州省教育厅青年科技人才成长(No.黔教合KY字[2018]126);中低品位磷矿及其共伴生资源高效利用国家重点实验室开放课题(No.WFKF2017-03)资助项目。

摘　　要：采用浸渍法制备了多钼氧簇/活性碳(PMoO/AC)非均相催化剂。通过傅里叶红外光谱仪(FT-IR)、X射线粉末衍射(XRD)、比表面积孔径测试仪(BET)、扫描电子显微镜(SEM)等方法对其进行表征。研究了其在过氧化氢氧化低浓度碘离子反应中的催化及重复使用性能;利用分子力学和量子化学方法对PMoO与AC之间的吸附进行模拟计算,研究其吸附机理。结果表明:在多钼氧簇的质量分数为40%、pH为1.8、过氧化氢的用量为3.6 mmol/L,催化剂的用量为1.0 g,反应温度为25℃条件下,反应速率为2.7×10-5 mol·L-1·s-1,较之未添加催化剂体系,反应速率提高了2.7×103倍,且具有较好的重复使用性;PMoO可以以物理吸附的方式吸附在活性炭表面,但其表面不同修饰基团对PMoO的吸附能甚至催化性能造成不同影响:OH和NH2修饰活性炭有利于增加PMoO的物理吸附稳定性,COOH修饰活性炭降低了其物理吸附能;改性基团均可以与PMoO键合发生化学吸附,提高体系稳定性,同时改变了PMoO的电子性质,使其最高占据轨道能级(HOMO)降低,使与反应物过氧化氢之间能隙减小,有利于催化反应的进行,其中,COOH修饰造成能级降低幅度最大。Polymolybdenum oxygen cluster/activated carbon(PMoO/AC)heterogeneous catalyst was prepared by impregnation method.The catalyst was characterized by Fourier infrared spectroscopy(FTIR),X-ray powder diffraction(XRD),specific surface area apeture tester(BET)and scanning electron microscope(SEM).Its catalysis and reuse performance in low concentration iodide ion oxidation by hydrogen peroxide were studied.The adsorption mechanism between PMoO and AC was studied by molecular mechanics and quantum chemistry.The results showed that the reaction rate reached 2.7×10-5 mol·L-1·s-1 under the condition that the mass fraction of polymolybdate oxygen cluster was 40%,the pH was 1.8,the concentration of hydrogen peroxide was 3.6 mmol/L,and the amount of catalyst was 1.0 g,Within 10 min,the conversion rate of iodide ion reached 99.7%,Compared to the system without catalyst,the reaction rate increased by 2.7×103 times and the conversion rate increased by 7.7%,and the catalyst has good reusability;PMoO can be adsorbed on the surface of activated carbon by physical adsorption,but different modified groups on the surface have different effects on the adsorption energy and even catalytic performance of PMoO:OH and NH2 can improve the physical adsorption stability of PMoO,while COOH can reduce the physical adsorption energy of activated carbon.All modified groups can be bonded with PMoO to form chemical adsorption,which could improve the stability of system.At the same time,the electronic properties of PMoO changed so as to lower the highest occupied orbital level(HOMO)and reduce the energy gap between them and the reactant hydrogen peroxide,which is conducive to the catalytic reaction.

关 键 词：多钼氧簇 活性炭 碘离子 非均相催化 

分 类 号：TQ032.4[化学工程]