V－Ag－Ni系氧化物的表面氧性质与甲苯选择性氧化的催化性能

制备了一系列Ｖ、Ａｇ、Ｎｉ原子比不同的三元氧化物，应用ＴＰＤ－ＭＳ技术研究了样品表面氧的性质，并测定了甲苯选择性氧化生成苯甲醛的催化活性．实验结果表明，样品表面存在有多种吸附的氧物种．在脱附温度＜９００℃：当Ｎｉ含量对Ａｇ（或Ｖ）的原子比为０．２５或０．５０时，仅在低温处出现有表面的Ｏ－和Ｏ２－两种氧物种的脱附峰；当Ｎｉ含量对Ａｇ（或Ｖ）的原子比增高到＞０．７５时，除有表面的Ｏ－和Ｏ２－两种氧物种的脱氧峰外，还有由于样品中的物相转变所生成的有晶格氧（Ｏ２－）参与脱附的脱氧峰．随着Ｖ－Ａｇ中Ｎｉ含量的改变，脱氧峰的脱附活化能Ｅｄ值也发生变化，３＃样品（Ｖ：Ａｇ：Ｎｉ＝１：１：０．７５）的Ｅｄ值最低，生成苯甲醛的选择性也最高．因此，样品的Ｅｄ值与生成苯甲醛的选择性之间存在着顺变关系．     

V-Ag-Ni系氧化物的表面氧性质与甲苯选择性氧化的催化性能

制备了一系列Ｖ，Ａｇ，Ｎｉ原子比不同的三元氧化物，应用ＴＰＤ－ＭＳ技术研究了样品表面氧的性质，并测定了甲苯选择性氧化生成苯甲醛的催化活性。实验结果表明，样品表面存在有多种吸附的氧物种。在脱附温度＜９００℃：当Ｎｉ含量对Ａｇ（或Ｖ）的原子比为０．２５或０．５０时，仅在低温处出现有表面的Ｏ＾－和Ｏ＾２＾－两种氧物种的脱附峰；当Ｎｉ含量对Ａｇ（或Ｖ）的原子比增高到＞０．７５时，除有表面的Ｏ＾－和Ｏ＾２＾     

Ag／γ—Al2O3催化剂的TPR和TPD研究

本文运用ＴＰＤ－ＭＳ，ＴＰＲ等方法研究了Ａｇ／γ－Ａｌ２Ｏ３催化剂的氧脱附和还原性能，结果表明，Ａｇ／γ－Ａｌ２Ｏ３催化剂表面银物相由Ａｇ＾０和Ａｈ＾＋（Ａｇ２Ｏ）组成，其中，Ａｇ＾＋所占比例随负载量增加而减少。     

甲醇燃料车尾气净化催化剂的研究Ⅲ甲醇深度氧化用Ag-Pd/γ-Al2O3催化剂中Ag与Pd的协同作用

以银氨络离子和氯钯酸铵为前驱体制备了５％Ａｇ－０．１％Ｐｄ／γ－Ａ２ｌＯ３催化剂，其低温深度氧化性能明显优于Ａｇ或Ｐｄ单组分催化剂；Ｔ５０和Ｔ９５（ＣＨ３ＯＨ）分别为１２５℃和１７０℃。且不受Ｏ２及ＣＯ的阻抑。Ｏ２－ＴＰＯ的结果表明，随着在Ａｇ组分中加入Ｐｄ及Ｐｄ加入量的增加，Ｏ２的低温脱附峰逐渐减弱至消失；中温脱附峰则向低温位移；高温脱附峰峰面积逐渐增大，峰温比单组分钯的氧脱附峰高。Ｐｄ与Ａｇ的     

铁钼氧化物TPD-MS及催化性能的研究

制备了一系列不同配比的Ｆｅ－Ｍｏ氧化物催化剂,采用比表面积,ＸＲＤ,ＦＴ－ＩＲ和ＬＲＳ等方法,考察了催化剂的有关物化性质,测定了对甲苯选择性氧化生成苯甲醛的催化活性。用ＴＰＤ－ＭＳ技术研究了催化剂表面氧物种的脱附。结果表明,随着样品中Ｆｅ／Ｍｏ含量的改变,表面氧物种的脱附峰的峰温,氧脱附量和脱附活化能Ｅｄ也发生变化。３＃样品的氧脱附峰峰温较低,表面氧物种Ｏ＾－和Ｏ＾２－脱附量最大,Ｅｄ值最小,生成     

La2—xSrxNiO4上氧的TPD及其氧化活性

Ｌａ２－ｘＳｒｘＮｉＯ４上Ｏ２的ＴＰＤ研究表明，氧的脱附性能与催化剂结构中Ｎｉ＾２＾＋和Ｎｉ＾３＾＋的性质及含量有关。晶格氧直接参与了ＣＯ的氧化与甲烷的氧化偶联。     

NO在Sm2—xSrxNiO4上的催化还原

在具有Ｋ２ＮｉＦ４型结构的Ｓｍ２－ｘＳｒｘＮｉＯ４（ｘ＝０．４，０．５，０．６，０．８，１．０，１．２，１．４，１．５）化合物上进行了ＣＯ催化还原ＮＯ的研究。结果表明，低温、低Ｓｒ＾２＋取借代量与高温、高Ｓｒ＾２＋取代量的反应途径不同，这可从化合物的结构、化合物中金属－氧键的标准生成焓的总和、ＮＯ还原的表现活化能及化合物上Ｏ２的脱附行为等得到解释。     

甲醇燃料车尾气净化催化剂的研究Ⅲ.甲醇深度氧化用Ag-Pd/γ-Al_2O_3催化剂中Ag与Pd的协同作用

以银氨络离子和氯钯酸铵为前驱体制备了５％Ａｇ０１％Ｐｄ／γＡｌ２Ｏ３催化剂，其低温深度氧化性能明显优于Ａｇ或Ｐｄ单组分催化剂；Ｔ５０和Ｔ９５（ＣＨ３ＯＨ）分别为１２５℃和１７０℃，且不受Ｏ２及ＣＯ的阻抑．Ｏ２ＴＰＤ的结果表明，随着在Ａｇ组分中加入Ｐｄ及Ｐｄ加入量的增加，Ｏ２的低温脱附峰（Ｔｐ＜２００℃）逐渐减弱至消失；中温脱附峰（２５０℃＜Ｔｐ＜４００℃）则向低温位移；高温脱附峰（Ｔｐ＞５００℃）峰面积逐渐增大，峰温比单组分钯的氧脱附峰高．Ｐｄ与Ａｇ的相互作用（电荷转移）是造成上述现象的原因．     

NO在Cu—ZSM—5分子筛上程序升温脱附研究

本文用等温动态吸附和程序升温脱附技术研究了ＮＯ与Ｃｕ－ＺＳＭ－５的相互作用，并根据还原预处理样品上ＮＯ吸、脱附循环的研究探讨了全过程样品所经历的氧化还原循环。在２５℃等温吸附时，ＮＯ与Ｃｕ＾＋和／或Ｃｕ＾０反应产生了Ｎ２、Ｎ２Ｏ和Ｃｕ＾２＋以及超晶格氧，同时在Ｃｕ＾＋上有许多可逆吸附的ＮＯ．ＮＯ吸附在Ｃｕ＾２＋上是稳定的。升高温度时，ＮＯ分为三种状态脱附，分别位于约１００，１８０和４００℃。后两种     

氧化铈对Pd／Al2O3表面上CO氧化性能的影响

采用ＴＰＤ－ＭＳ及ＴＰＳＲ－ＭＳ技术研究了添加ＣｅＯ２对Ｐｄ／Ａｌ２Ｏ３催化剂上ＣＯ脱附、表面反应及表面氧脱附等性能的影响，考察了不同含氧量的气氛下ＣＯ的氧化活性，结果表明，Ｐｄ－Ｃｅ间的相互作用有利于各自原子上表面氧的吸脱附及ＣＯ的表面反应，并发现ＣＯ２脱附量大小及峰温次序与对ＣＯ的催化氧化活性有一致的对应关系。     

Studies on Kinetic Properties of Active Oxygen on the Surfaces of V_2O_5/SiO_2, V_2O_5-MoO_3/SiO_2 and V_2O5-P_2O5/SiO_2 Catalysts

Applying the TPD-MS with a high sensitivity of determination, the TPD spectrum of surface oxygen of V2O5/SiO2, V2O5-MoO3/SiO2 and V2O6-P2O5/SiO2 catalysts was obtained. The surface oxygen of these catalysts can be divided into three groups according to the desorption temperature. O2- desorbs mainly from 373K. to 423K, O- from 673K to 873K and O2- at above 873K. The activation energy and frequency factor of all the three kinds of oxygen species were calculated. Based on these results, the mechanism of oxygen desorption and the influence of P2O5 and MoO3 on the properties of oxygen supply of V2O5/SiO2 catalst were investigated. MoO3 and a small amount of P2Os increase the number of supplying oxygen and increase the activity of O- species. A large amount of P2O5 increases the number of supplying oxygen and restrains the activity of O- species.     

五氧化二钒插层纳米复合材料的组装与电化学性能

五氧化二钒具有二维空间层状结构,层间伸缩性好,具有纳米尺寸,且有可做成无定形、高比表面积的溶胶.凝胶、干凝胶、气凝胶和类气凝胶等多种形态的优点.目前以其为主体的插层纳米复合材料研究十分活跃,本文综述了近年来合成的五氧化二钒插层化合物的组装及其电化学性能研究的进展.     

V2O5在载体表面的分散状态与表面酸性

用ＸＲＤ，ＸＰＳ研究了Ｖ２Ｏ５在γ－Ａｌ２Ｏ３，ＳｉＯ２，ＴｉＯ２等载体上的分散状态，测定了最大分散容量。结果表明，Ｖ２Ｏ５在γ－Ａｌ２Ｏ３和ＳｉＯ２上能形成亚单层分散，分散容量分别为理论单层量的６０％和４５％；Ｖ２Ｏ５在ＴｉＯ２上优先形成单层，然后形成多层结构。Ｖ２Ｏ５在γ－Ａｌ２Ｏ３上分散可使表面酸性有所增加；Ｖ２Ｏ５在ＳｉＯ２上分散使表面酸性剧增，酸位数和表面Ｖ＾５＋的摩尔比高达０．５左右；     

3D porous V_2O_5 architectures for high-rate lithium storage

The discovery of novel electrode materials promises to unleash a number of technological advances in lithium-ion batteries. V_2O_5 is recognized as a high-performance cathode that capitalizes on the rich redox chemistry of vanadium to store lithium. To unlock the full potential of V_2O_5, nanotechnology solution and rational electrode design are used to imbue V_2O_5 with high energy and power density by addressing some of their intrinsic disadvantages in macroscopic crystal form. Here, we demonstrate a facile and environmental-friendly method to prepare nanorods-constructed 3D porous V_2O_5 architectures(3 D-V_2O_5)in large-scale. The 3D porous architecture is found to be responsible for the enhanced charge transfer kinetics and Li-ion diffusion rate of the 3D-V_2O_5 electrode. As the result, the 3D-V_2O_5 surpasses the conventional bulk V_2O_5 by showing enhanced discharge capacity and rate capability(delivering 154 and127 m Ah g~(-1) at 15 and 20 C, respectively).     

V_2O_5/C电化学电容器有机电解液的性能研究

以偏钒酸铵为反应原料,采用液相沉淀法制备出不定型V2O5电极材料.以V2O5为正极,石墨为负极,分别选用1.0 mol/L LiClO4/EC+DMC、1.0 mol/L LiPF6/EC+DEC+DMC、1.6 mol/L Et4NBF4/AN 3种有机电解液组成不对称电化学电容器,恒流充放电、循环伏安和交流阻抗等测试该模拟电容器,如以1.0 mol/LLiClO4/EC+DMC作电解液则具有良好的循环性能和较小的阻抗,且在500 mA/g电流密度下比能量达到8.4Wh/kg,充放电效率达98%.     

Electrochemical and structural evolution of structured V_2O_5 microspheres during Li-ion intercalation

With the development of stable alkali metal anodes,V₂O₅ is gaining traction as a cathode material due to its high theoretical capacity and the ability to intercalate Li,Na and K ions.Herein,we report a method for synthesizing structured orthorhombic V₂O₅ microspheres and investigate Li intercalation/deintercalation into this material.For industry adoption,the electrochemical behavior of V₂O₅ as well as structural and phase transformation attributing to Li intercalation reaction must be further investigated.Our synthesized V₂O₅ microspheres consisted of small primary particles that were strongly joined together and exhibited good cycle stability and rate capability,triggered by reversible volume change and rapid Li ion diffusion.In addition,the reversibility of phase transformation(a,e,d,c and xLixV₂O₅)and valence state evolution(5+,4+,and 3.5+)during intercalation/de-intercalation were studied via in-situ X-ray powder diffraction and X-ray absorption near edge structure analyses.     

纳米负载型V_2O_5-WO_3/TiO_2催化剂碱中毒及再生研究

实验制备了陶瓷颗粒为骨架的纳米级V2O5-WO3/TiO2(C)催化剂。采用浸渍法模拟碱金属中毒,研究了中毒及再生对催化剂脱硝活性的影响,运用XRD、FT-IR、H2-TPR、XPS技术表征分析了碱金属对催化剂的失活作用。实验表明,碱金属能使催化剂活性降低,钾的毒性大于钠。FT-IR结果显示,催化剂以Lewis酸作为活性酸位。H2-TPR、XPS结果表明,钾的加入降低了催化剂的氧化能力,主要影响了催化剂表面的吸附氧。采用单纯的水洗方法并不能提高催化剂活性,而酸洗再生后催化剂在较高反应温度下活性得到较好的恢复。     

CO2在Cu-Ni/V2O5-SiO2催化剂上的吸附与反应

二氧化碳;复合氧化物;双金属催化剂;表面反应;CO2在Cu-Ni/V2O5-SiO2催化剂上的吸附与反应     

Insights into the H_2O/V_2O_5 Interface Structure for Optimizing Water-splitting

The interaction of water(H2O) with metal oxide surfaces is of fundamental importance to various fields of science, ranging from batteries to catalysis. In particular, vanadium pentoxide(V2O5) has been widely used as electrode materials for aqueous-battery and catalysts. Herein, theoretical(density functional theory) study gives atomic-scale insights into water monolayers in V2O5 and single-molecule adsorption and dissociation at three low-index surfaces and oxygen-vacancy V2O5(001) surface. The H2O/V2O5 interface structure was identified. The results show that H2O is adsorbed on the stoichiometric V2O5(001) surface with physisorption mechanism, and the dissociation hardly occurs. Water adsorbs as an intact monomer with a computed binding energy of 0.75 eV. The formation of ordered water overlayers has been observed on V2O5(001) surface, suggesting a locally ordered superstructure of molecular water. The molecular H2O adsorption on oxygen-vacancy V2O5(001) surface is stronger than that on the stoichiometric V2O5(001) surface, and H2O can undergo dissociative chemisorption to form a surface hydroxyl group and a H adatom. V2O5 can take the oxygen from H2O, which is consistent with the experimental results.     

V2O5/AC捕获的Hg在再生过程中的释放行为研究

研究了V₂O₅/AC捕获的Hg在再生和程序升温脱附（TPD）过程中的释放行为,考察了再生后V₂O₅/AC对Hg⁰的捕获能力。结果表明,热再生（Ar,400℃）或NH₃再生（NH₃/Ar,300℃）过程会使V₂O₅/AC捕获的大部分Hg重新释放,释放率分别为81%和94%。由于AC的还原作用,再生过程中释放的Hg以Hg⁰的形式为主。TPD结果表明,V₂O₅/AC捕获的Hg在Ar和NH₃/Ar气氛下的释放行为明显不同。气氛中NH₃对Hg的释放具有明显的促进作用,使Hg的释放在300℃前基本结束。但在Ar气氛下,Hg在400℃后仍有释放,致使热再生时Hg的释放率低于NH₃再生时的释放率。但当NH₃的体积分数由1%增加到5%时,汞的释放率变化很小。温度足够高时,两种气氛下Hg的释放率趋于一致。再生方法对V₂O₅/AC二次捕获Hg⁰的能力影响不大,两种气氛下再生后的V₂O₅/AC对Hg⁰的捕获能力差别很小,较新鲜V₂O₅/AC对Hg⁰的捕获能力有所降低,但仍高于载体AC对Hg⁰的捕获能力.