基于Dawson型磷钼酸盐(NH4)6P2Mo18O62(P2Mo18)可逆的氧化还原及变色性质,利用紫外-可见光谱可实现P2Mo18溶液对水合肼(N2H4·H2O)及过氧化氢(H2O2)的可逆检测.在P2Mo18溶液中加入等量N2H4·H2O后,P2Mo18被还原,溶液由浅黄色变为蓝绿色,随着N2H4·H2O浓度的增加,在可见区400～800 nm的吸收峰逐渐增强;在还原态P2Mo18溶液中加入等量H2O2后,还原态P2Mo18重新被氧化,溶液由蓝绿色变为浅黄色,随着H2O2浓度的增加,在可见区的吸收峰逐渐降低.以750 nm处的吸光度对N2H4·H2O和H2O2的浓度做图,获得紫外-可见光谱法对N2H4·H2O和H2O2检测的线性方程、线性检测范围及检出限,并利用紫外-可见动力学法和光谱法对该探针的响应时间、可逆性及抗干扰性进行研究.结果表明:该方法对N2H4·H2O和H2O2的检出限分别为7.24×10-5,2.15×10-4 mmol/L;对N2H4·H2O和 H2O2检测的响应时间分别为44.8,23.9 min.

以硅钨酸(H4SiW12O40)为催化剂、介孔分子筛SBA-15为载体,将浸渍法与焙烧法相结合制备了一系列介孔分子筛固载硅钨酸复合催化剂SiW12/SBA-15;并利用红外光谱(FTIR)、粉末X-射线衍射(XRD)、N2吸附-脱附、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等对其组成、结构及形貌进行表征.将此催化剂用于催化合成柠檬酸三丁酯的酯化反应中,考察酸醇摩尔比、催化剂用量、反应温度、反应时间对催化合成柠檬酸三丁酯酯化率的影响;研究不同焙烧温度对催化剂重复使用性能的影响,获得固载型催化剂制备的最佳焙烧温度为380℃.

以3-(甲基丙烯酰氧)丙基三甲氧基硅烷(MEMO)表面改性的介孔分子筛SBA-15为载体,制备了一系列介孔分子筛/硅烷偶联剂@杂多酸复合催化剂SBA-15/MEMO@HnXW12O40(X=P5+,Si4+,B3+;n=3,4,5),并利用FTIR、P-XRD、TEM、N2吸附-脱附对其结构进行表征.以SBA-15/MEMO@Hn XW12 O40(X=P5+,Si4+,B3+;n=3,4,5)为负载型杂多酸催化剂对柠檬酸三丁酯的催化合成进行研究,分别考察了酸醇摩尔比、催化剂用量、反应温度、反应时间对催化合成柠檬酸三丁酯酯化率的影响,并获得合成柠檬酸三丁酯的最佳工艺条件.结果表明:当负载型硅钨酸催化剂的负载量为50％、催化剂用量为3.8％、酸醇摩尔比为1:4、反应温度为140℃、反应时间为6 h、环己烷用量为5 mL时酯化率可达97.56％,重复使用7次后酯化率仍可达62.67％.

各级各类学科竞赛已经成为高校培养创新型人才的重要途径,也是提升大学生创新能力和实施素质教育的平台.本文以内蒙古民族大学为对象,从民族高等院校开展学科竞赛的意义出发,结合近年来学校开展学科竞赛的举措和成效,阐述了积极开展学科竞赛的意义,即有利于培养大学生理论与实践相结合的创新意识和创新精神,对提高大学生实践创新能力具有积极促进作用.

以3-氨丙基三乙氧基硅烷改性的SBA-15为载体,以具有不同组成的Keggin型磷钨钼杂多酸H3 PWnMo12-nO34(n=0,6,12)为固体酸催化剂,通过对SBA-15表面修饰获得一系列介孔分子筛/硅烷偶联剂@磷钨钼杂多酸复合催化剂PWMo@SBA-15/Apts,并利用FTIR、P-XRD、TEM、N2吸附-脱附对复合催化剂的组成、结构及形貌进行了表征.以PWMo@SBA-15/Apts为催化剂对柠檬酸三丁酯的催化合成进行研究,考察不同多酸组成、催化剂用量、酸醇物质的量比、反应时间、反应温度对催化合成柠檬酸三丁酯酯化率的影响.结果表明:固载磷钨酸催化剂合成柠檬酸三丁酯的酯化率最高可达97.36％,重复使用8次后酯化率仍可达74.38％.

In this paper, the luminescent properties of rare earth containing polyoxometalates were investigated by combining theory with experiment.Firstly, a series of rare earth containing polyoxometalates clusters Na9LnW10O36 (Ln 3+ = Sm 3+ , Eu 3+ , Tb 3+ , Dy 3+ ) were synthesized by the conventional aqueous solution synthesis method.Secondly, the structure of clusters was characterized by powder X-ray diffraction, FTIR spectroscopy and Raman spectroscopy.Finally, the optical properties of the clusters were investigated by UV-Vis spectra and fluorescence spectra.Through systematic experiments, students have a comprehensive and profound understanding of the structure characterization and luminescence properties of rare earth clusters.

为了提高学生对大型仪器在化合物结构表征、 性质研究及实际应用能力,利用水溶液回流法合成了Dawson型多酸(NH4)6 P2 Mo18 O62,并利用FTIR、Raman、UV-Vis与CVs对多酸的结构与光电活性进行研究;分别用UV-Vis光谱及动力学法对维生素C光谱检测的检出限、检测范围、响应时间、选择性及可重复使用性进行研究;通过系统性实验训练全面培养学生综合设计、科研创新、实际应用等能力.

A series of complexes of surfactant@polyoxoanions were prepared by water/chloroform two-phase electrostatic encapsulating technology, employing polyoxoanion CeW10O369- with high photocatalytic activity and cationic surfactants in different structure as building blocks. The composition and structure of the complexes were analyzed by Fourier infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The effects of various surfactants, catalyst dosage, concentration of methyl orange, and organic dyes on the photocatalytic degradation rate were investigated, in which methyl orange and surfactant@polyoxoanions complexes were used as photodegradation substrate molecule and photocatalyst, respectively. The photodegradation activities for different composite catalysts of surfac-tant@polyoxoanions are in the order of DTAB (dodecyltrimethylammonium bromide)@CeW10>TTAB (tetradecyltrimethylammonium bromide)@CeW10>CTAB (cetyltrimethylammonium bromide)@CeW10>OTAB (octadecyl trimethyl ammonium bromide) @CeW10>DODA (dioctadecyl dimethyl ammonium bromide)@CeW10.

以不同硅烷偶联剂改性的介孔分子筛SBA-15为载体、PW12为催化剂,通过对SBA-15表面共价及非共价修饰制备磷钨酸@介孔分子筛/硅烷偶联剂复合催化剂PW12@SBA-15/YSiX3(YSiX3=Apts、Atapts、Papts);并利用FT-IR、XRD、TEM、N2吸附-脱附对其组成、结构及形貌进行表征.以改性SBA-15分子筛固载磷钨酸催化剂催化合成叔丁基苯酚为研究对象,考察不同硅烷偶联剂、反应温度、苯酚与叔丁醇物质的量比对催化合成叔丁基苯酚的影响,并获得合成叔丁基苯酚的最佳工艺条件,即反应温度145℃、n(苯酚):n(叔丁醇)=1:2.5、重时空速2.2 h-1,该最佳反应条件下,PW12@SBA-15/Apts催化剂催化合成叔丁基苯酚的催化活性最高,苯酚转化率为98.3％,2,4-二叔丁基苯酚选择性为57.3％.

Hierarchical aluminum-silicon materials have been successfully prepared by mixing pre-crystallization of silica-alumina sol and citric acid under hydrothermal conditions. The influence of pre-crystallization time on the micro-mesoporous structure is studied using Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), N2 physical adsorption, and high-resolution transmission electron microscopy (HRTEM). The catalytic performance of hierarchical silica-alumina material is evaluated by alkylation of phenol with tert-butanol. The results show that the silica-alumina materials with a pre-crystallization time of 16 h show micro-mesoporous structure and excellent catalytic activity.

Using polyethylene glycol as a mesoporous soft template, a series of hierarchically porous ZSM-5 zeolites were prepared. X-ray diffraction, infrared spectroscopy, N2 adsorption–desorption, and transmission electron microscopy results demonstrated that the resultant materials contained a micro–mesoporous structure. Since the existence of mesoporous structure favors the diffusion of large molecular reactants and products, the phenol conversion and selectivity to 2,4-Di-TBP on the hierarchical ZSM-5 zeolite can be improved for the alkylation of phenol with tert-butanol.

A series of Keggin-type heteropoly acids HnXW12O40 (X=P5+, Si4+, B3+;n=3, 4, 5) were synthesized by ion exchange method.The structures were characterized by XRD and FTIR spectrum.The Keggin-type heteropoly acids were used as the molecular type homogeneous catalysts and the synthesis of tributyl citrate was studied.The catalytic activity of three kinds of Keggin-type heteropoly acids HnXW12O40 (X=P5+, Si4+, B3+;n=3, 4, 5) with different central heteroatoms and external hydrogen ions in the synthesis of tributyl citrate was compared.The effects of catalyst dosage, acid-alcohol molar ratio, reaction time and reaction temperature on the catalytic synthesis of tributyl citrate esterification rate were investigated.Finally, the optimum technological conditions for the synthesis of tributyl citrate were obtained.

首先,以微孔结构的ZSM-5沸石为前驱物,经碱液处理不同时间后与介孔模板剂十六烷基三甲基溴化铵(CTAB)混合,水热处理后制备微孔-介孔ZSM-5分子筛,并用X射线衍射(XRD)、Fourier变换红外光谱(FT-IR)、N2吸附-脱附和透射电镜(TEM)等方法表征微孔-介孔ZSM-5分子筛的理化性质.其次,将微孔-介孔ZSM-5分子筛作为苯酚叔丁醇烷基化反应的催化剂,利用苯酚转化率与2,4-二叔丁基苯酚的选择性测试所得材料的催化性能.结果表明:碱处理1 h可获得微孔和介孔复合较好的ZSM-5,且该催化剂具有较好的苯酚叔丁基化催化性能,苯酚的转化率最高为86.2％,大分子2,4-二叔丁基苯酚的选择性可达57.9％.

Flexible self-supporting TbW10-agarose composite thin films were prepared by combination of Sol-Gel and casting technique based on the functional complementarity between excellent green luminescence polyoxometalates TbW10 and good film-forming matrix agarose. Composition and structure of the films were characterized by FT-IR and Raman spectrum. Thir thickness, surface roughness and microstructure were studied by SEM, AFM and TEM, respectively. And effects of different TbW10 contents on the transmittance and luminescence properties were investigated. On this basis, the reversible chemically responsive luminescent switching performance of TbW10-Agarose green luminescent film was realized under stimulation of HCl and NH3. The response time and reversibility of chemically responsive luminescent switching performance were studied by fluorescence kinetics curves. And the fluorescence spectrum detection for HCl gas was extended based on the green luminescent thin film sensor with a detection limit of 0.2731 mmol.L-1.

Based on the functional complementarity between the reversible electrochromic property of the Dawson type polyanions P2W18O626- and the excellent luminescent property of Tb3+, the reversible electrochromic and luminescent switching properties of P2W18O626-@TB3+ mixed solution were achieved under redox potential stimulation. The effects of applied reduction potential on electrochromic response time and the energy transfer efficiency of luminescent switch were investigated. And the energy transfer efficiency of the mixed solution P2W18O626-@Tb3+ were 85.97%, 87.53% and 93.42% when applied different reduction potential -0.38, -0.69 and -0.85 V, respectively. On this basis, the UV-Vis and fluorescence spectroscopy bi-functional detection for H2O2 were realized by combining electrochemical reduction with chemical oxidation methods. The detection limits for H2O2 were 1.76x10(-2) and 3.04 mu mol.L-1 by the UV-Vis and fluorescence spectroscopy, respectively.

基于变色多酸P 2 Mo 18 O 62 6- 与绿光Tb 3+ 之间的功能互补及分子间能量转移的原理，在维生素C（VC）的还原下，P 2 Mo 18 O 62 6- @Tb 3+ 溶液由浅黄色变为蓝色，发生荧光猝灭；相反，在H 2 O 2 氧化下，溶液的蓝色褪去，荧光得以恢复，P 2 Mo 18 O 62 6- @Tb 3+ 溶液呈现出可逆的化学响应变色及荧光开关性质.利用紫外-可见（UV-Vis）及荧光（PL）光谱法对VC浓度进行定量检测，分别以800 nm处的吸光度和547 nm处荧光强度的对数值对VC浓度作图，获得光谱法对VC检测的线性方程，检出限分别为3.40×10 -3 和0.21 μmol/L；利用UV-Vis及PL动力学方法对VC和H 2 O 2 检测的响应速度进行了考察，响应时间分别为52和320 s；通过UV-Vis光谱及动力学方法考察了VC检测的选择性及可重复使用性.

Micro-mesoporous ZSM-5/SBA-15 molecular sieve was derived from mesoporous molecular sieves SBA-15 by hydrothermal crystallization approach. The silica-alumina ratio significantly affects the structure and catalytic performance of ZSM-5/SBA-15. When the $$\hbox {n}_{\mathrm{Si}}\hbox {/n}_{\mathrm{Al}}$$ is less than 25, the two-dimensional hexagonal pore structure of SBA-15 keeps intact with relatively low crystallinity of the pore wall. However, when the $$\hbox {n}_{\mathrm{Si}}\hbox {/n}_{\mathrm{Al}}$$ is larger than 50, the SBA-15 pores are severely damaged. When $$\hbox {n}_{\mathrm{Si}}\hbox {/n}_{\mathrm{Al}}$$ is 25, the catalyst ZSM-5/SBA-15 retains relatively good pore structure and shows excellent catalytic performance with 96.2% phenol conversion and 53.5% selectivity to 2,4-ditert-butyl phenol in the tert-butylation of phenol. SYNOPSIS Micro-mesoporous ZSM-5/SBA-15 molecular sieve was derived from mesoporous molecular sieve SBA-15 by hydrothermal crystallization approach. ZSM-5/SBA-15 ( $$\hbox {n}_{\mathrm{Si}}\hbox {/n}_{\mathrm{Al}}=25$$ ) retains relatively good pore structure and shows excellent catalytic performance with 96.2% phenol conversion and 53.5% selectivity to 2,4-ditert-butyl phenol in the tert-butylation of phenol. Effect of silica-alumina ratio of micro-mesoporous silica ZSM-5/SBA-15 on the catalytic performance of tert-butylation of phenol

采用NaOH溶液对ZSM-5分子筛进行不同时间预处理,再以柠檬酸为成孔剂,在水热条件下合成了微孔-介孔ZSM-5分子筛,考察碱处理时间对分子筛内部孔道结构的影响.同时测试了分子筛在苯酚叔丁基化反应中的催化活性.结果 表明,ZSM-5分子筛经1 mol/L的NaOH溶液处理1h后加入柠檬酸搅拌2h,于100℃条件下晶化24 h所形成的微孔-介孔ZSM-5分子筛具有良好的微孔和介孔复合结构.在苯酚叔丁基化反应中表现出良好的催化性能,在反应温度为145℃时,苯酚的转化率为85.6％,2,4-二叔丁基苯酚的选择性为60.2％.

Based on the functional complementarity and energy transfer between the reversible discoloration polyoxoanions P2Mo18O626- and green luminescent Tb3+ ions, the color of the P2Mo18O626-@Tb3+ mixed solution changed from light yellow to dark blue and as meanwhile the luminescence quenched under the reduction of VC. On the contrary, the dark blue color faded and the luminescence recovered correspondingly under the oxidation of H2O2. And the P2Mo18O626-@ Tb-3(+) mixed solution exhibited a reversible chemical response discoloration and luminescent switching properties. The VC concentrations were quantitatively measured by UV-Vis and PL spectroscopy, and the corresponding linear equations were acquired by drawing VC concentrations with UV-Vis absorbance at 800 nm and fluorescence intensity at 547 nm. And the detection limits were 3. 40x10(-3) and 0. 21 mu mol/L , respectively. The response rates of VC and H2O2 detection were investigated by UV-Vis and fluorescence kinetic methods, and the response time were 52 and 320 s, respectively. Finally, the selectivity and reusability of VC detection were studied by UV-Vis spectroscopy and kinetic methods.

通过浸渍法分别将磷钨酸、磷钼酸负载于MCM-48分子筛内,制备负载型杂多酸催化剂,并采用傅里叶变换红外光谱(FT-IR)、N2吸附-脱附、X射线衍射(XRD)等方法对负载型催化剂进行表征.将负载型杂多酸催化剂应用于乳酸丁酯合成反应,在催化剂用量及反应温度确定的条件下,考察了正丁醇和乳酸物质的量比、杂多酸负载量、反应时间对酯化率的影响.结果 表明,MCM-48分子筛分别负载磷钨酸和磷钼酸是合成乳酸丁酯较为理想的催化剂,在最佳条件下,催化合成乳酸丁酯酯化率在94％以上,且负载型催化剂回收容易,可重复使用.