用于乙醛酸电合成的高效表面合金电催化剂研究

运用电化学方法，研制了三种表面合金（Ｐｂ－Ｓｂ－Ｐｔ／ＧＣ，Ｓｂ－Ｐｔ／ＧＣ，Ｐｂ－Ｐｔ／ＧＣ）电催化剂，发现在草酸还原生成乙醛酸的电有机合成中这些表面合金电催化有较高的活性，其起始还原电位分别比在Ｐｂ阴极上（－１．１Ｖ）提前了０．４８～０．７０Ｖ，这三种表面合金电催化剂的活性次序为：Ｐｂ－Ｓｂ－Ｐｔ／ＧＣ〉Ｓｂ－Ｐｔ／ＧＣ〉Ｐｂ－Ｐｔ／ＧＣ。红外光谱结果表明，在这些表面合金电极上草酸还原产物主要     

NaY超笼内[Pt3(CO)3(μ-CO)3]^2-n(n=3,4)簇合物的合成,表征及其催化CO+NO的反应性能

在ＮａＹ分子筛超笼内合成了桔黄色的［Ｐｔ９（ＣＯ）１６］＾２－和深绿色的［Ｐｔ１２（ＣＯ）２４］＾２－簇合物。前者给出２０５６和１７９８ｃｍ＾－１的线式和桥式羰基特征红外谱带；后者给出２０８０和１８２４ｃｍ＾－１谱带。与在ＴＨＦ溶液中结果相比，ＮａＹ内合成的羰基簇合物的线式ｖｃｏ向高波数位移，而桥式ｖｃｏ向低波数位移。ＥＸＡＦＳ为Ｐｔ羰基簇合物在分子筛内的规整形成提供了证据。ＮａＹ内Ｐｔ９和Ｐｔ１     

cis－［Pt（NH_3）_2Cl_2］和trans－［Pt（NH_3）_2Cl_2］的微型合成

ｃｉｓ－［Ｐｔ（ＮＨ_３）_２Ｃｌ_２］和ｔｒａｎｓ－［Ｐｔ（ＮＨ_３）_２Ｃｌ_２］的微型合成袁书玉，来月英（清华大学化学系，北京１０００８４）ｃｉｓ－［Ｐｔ（ＮＨ２）２Ｃｌ２］为一抗癌药物，而它的反式异构体却没有这一特性。其原因也已在进行研究［１］。由...     

离子基碳——氧键断裂能量的研究（II）——负离子基的键能

合成了３个系列芳香类含碳－氧键的化合物，用循环伏安法测定了相关的氧化还原电势，通过热力学循环首次估测了负离子基的碳－氧键的断裂能量（ΔＨｃｌｅａｖ［Ｃ－Ｏ］＾－）。结果表明：得到１个电子形成负离子基可以活化碳－氧键。这与具有相同结构的正离子基的情况是一致的，但其活化程度略小。相关分析表明：ΔＨｃｌｅａｖ［Ｃ－Ｏ］＾－ｖｓ．（ΔＥｒｅｄ［Ｃ－Ｏ］＋ΔｐＫａ［ＨＡ］和ΔＨｃｌｅａｖ［Ｃ－Ｏ］＾＋ｖｓ．     

Cu-ZSM-5分子筛上[Cu-O-Cu]2+物种的原位红外光谱研究

通过原位监测Ｃｕ－ＺＳＭ－５分子筛的振动动红外光谱随温度及不同处理条件的变化情况,观察到［Ｃｕ－Ｏ－Ｃｕ］＾２＋物种的形成过程,即两个Ｃｕ（ＯＨ）＾＋在脱水过程中经二聚形成［Ｃｕ－Ｏ－Ｃｕ］＾２＋,低交换度样品开始产生［Ｃｕ－Ｏ－Ｃｕ］＾２＋物种所需脱水温度较高,通过观察不同处理条件对［Ｃｕ－Ｏ－Ｃｕ］＾２＋的影响,说明Ｃｕ＾２＋是通过脱出［Ｃｕ－Ｏ－Ｃｕ］＾２＋中的超各氧而被还原为Ｃｕ＾＋,较高     

利用质谱—质谱法进行稠环芳烃化合物的结构解析

应用（ＥＩ）ＭＳ／ＭＳ法研究了吡啶并苯并蒽酮以及苯并苯并蒽酮类异构体的裂解方式及其与结构之间的相关性，探讨了不同异构体中由Ｍ＾ｉ＋产生的［Ｍ－Ｈ］＾＋、［Ｍ－ＨＣＮ］＾＋、［Ｍ－ＣＯＨ］＾＋、［Ｍ－ＣＯ］＾ｉ＋、［Ｍ－（ＣＯ＋２Ｈ）］＾ｉ＋以及［Ｍ－（ＣＯ＋ＨＣＮ）］＾ｉ＋（ｉ＝１，２）等１价及２价离子在ＭＳ／ＭＳ－ＣＩＤ谱上的强度差异和裂解方式，发现是否含有氮原子以及氮原子和苯环位置的差异，是支     

偶氮氯膦Ⅲ—希土极谱络合吸附波的研究

在０．０６ｍｏｌ／Ｌ ＮａＡｃ－ＨＡｃ ｐＨ４．５的缓冲底液中，偶氮氯膦Ⅲ（ＣＰＡⅢ）在－０．２５Ｖ（ｖｓ．Ａｇ／ＡｇＣｌ）有一良好的微分脉冲极谱还原波，加入希土（ＲＥ）后期峰高电流（ｉｐ）降低，轻希土浓度在１×１０＾－６～６×１０＾－６ｍｏｏ／Ｌ，钇和重希土浓度在２×１０＾－７～３×１０＾－６ｍｏｌ／Ｌ范围中，ｉｐ的降低与浓度呈线性关系，表明ＣＰＡⅢ亦是可用的希土极谱分析试剂。实验证明它们是不可     

Studies of surface alloy as high efficient electrocatalyst for glyoxylic acid synthesis

运用电化学方法，研制了三种表面合金（ＰｂＳｂＰｔ／ＧＣ，ＳｂＰｔ／ＧＣ，ＰｂＰｔ／ＧＣ）电催化剂，发现在草酸还原生成乙醛酸的电有机合成中这些表面合金电催化剂有较高的活性，其起始还原电位分别比在Ｐｂ阴极上（１．１Ｖ）提前了０．４８～０．７０Ｖ。这三种表面合金电催化剂的活性次序为：ＰｂＳｂＰｔ／ＧＣ＞ＳｂＰｔ／ＧＣ＞ＰｂＰｔ／ＧＣ。红外光谱结果表明，在这些表面合金电极上草酸还原产物主要为乙醛酸。     

尾式卟啉铁(Ⅲ)电化学性质研究──Ⅱ．二甲胺基/二乙胺基尾式卟啉铁轴向效应的循环伏安行为

本文用循环伏安法研究了一类新型生物模型化合物－氯化－间－［邻－（４－二甲胺基／二乙胺基丁酰胺基苯基）三苯基］卟啉铁（Ⅲ）在不同抗衡阴离子、ＮＯ及轴向含Ｎ有机碱存在下的电化学行为。结果表明：（１）抗衡阴离子对电对Ｆｅ（Ⅲ）／Ｆｅ（Ⅱ）半波电位的影响顺序为Ｃｌ＾－＞Ｂｒ＾－＞ＯＡｃ＾－＞ＣｌＯ＾－４，对电对Ｆｅ（Ⅱ）／Ｆｅ（Ⅰ）的影响则相反。（２）ＮＯ的配位改变了尾端叔胺的配位状态，由于ＮＯ与铁卟啉配     

四磺酸酞菁铜—DDAB表面活性剂薄膜电极对卤代乙酸的电化学催化

四磺酸酞菁铜阴离子（ＣｕＰｃＴｓ＾４－）在水溶液中可借助离子交换进入阳离子表面活性剂双十二烷基二甲基溴化铵（ＤＤＡＢ）薄膜电极，从而形成ＣｕＰｃＴＳ＾４－－ＤＤＡＢ薄膜电极，循环伏安实验表明，在ＫＢｒ溶液中，该薄膜电极有一对良好的还原氧化峰，阴阳极峤电位分别为－０．７８Ｖ和－０．６５Ｖ（ｖｓ．ＳＣＥ）．探讨了该薄膜电极的电化学行为，特别是对其各种卤代乙酸的电化学催化，对其机理进行了推测。     

侧基上带有C60基团的聚苯乙烯的表征

用UV、FTIk、DSC、TG和DTA及GPC等方法证明了通过三步反应(氯甲基化,叠氮化,环加成反应)确实将C₆₀引入到聚苯乙烯的侧基上,C₆₀基本上以单取代的方式存在,并通过TG和DTA方法估算了C₆₀在聚苯乙烯C₆₀衍生物中的含量。     

C60电化学还原的稳态性质研究

自1990年9月Kratschmer等报导了C_(60)的常量制备和提纯以来,有关C_(60)及其他富勒炭分子(Fullerens)的研究报导与日俱增,成为近三年来最为活跃的研究领域之一.由于C_(60)的特殊结构,在电化学行为上也表现出十分独特的反应性质,如容易实现多电子氧化还原反应,可逆加氢及能形成离子嵌入电极材料等.本工作采用微电极方法研究了C_(60)稳态极化行为,测定了C_(60)的扩散系数和反应电子数,并通过现场紫外可见光谱电化学方     

Fullerene adlayers on various single-crystal metal surfaces prepared by transfer from L films

Fullerene adlayers prepared by the simple Langmuir-Blodgett (LB) method onto various well-defined single-crystal metal surfaces were investigated by in situ scanning tunneling microscopy (STM). The surface morphologies of fullerene adsorbed onto metal surfaces depended largely on the adsorbate-substrate interactions, which are governed by the types of surfaces. Too weak adsorption of C60 molecules onto iodine-modified Au(111) (I/Au(111)) allows surface migration of the molecules, and then, STM cannot visualize the C60 molecules. Stronger and appropriate adsorption onto bare Au(111) leads to highly ordered arrays relatively easily due to the limited surface migration of C60. On iodine-modified Pt(111) (I/Pt(111)) and bare Pt(111) surfaces, which have stronger adsorption, randomly adsorbed molecular adlayers were observed. Although C60 molecules on Au(111) were visualized as a featureless ball due to the maintenance of the rapid rotational motion (perturbation) of C60 on the surface at room temperature, those on I/Pt(111) revealed the intramolecular structures, thus indicating that the perturbation motion of molecules on the surface was prohibited.     

Pt(PPh3)2-η2C60络合物的分子轨道研究

近年来,自Kratschmer 等人采用并不复杂的方法就能制备出宏观量的C_(60),人们对它的兴趣也从结构的研究逐渐转向化学性质的研究.C_(60)是目前自然界已知对称性最高的球状分子,每个C 原子都以接近sp~2杂化轨道和相邻的三个C 原子相联.C_(60)的NMR 化学位移以及闭壳层的电子结构和较宽的HOMO-LUMO 间隙,都说明它具有典型的芳香化合物——苯的某些特性.另外,掺杂(碱金属元素)后,它具有的导电性又表现出石墨具有的某些特点.     

Electrocatalytic properties of Pt(111), Pt(332), Pt(331) and Pt(110) single crystal electrodes towards ethylene glycol oxidation in sulphuric acid solutions

In the present paper four platinum single crystal electrodes, two basal planes of Pt(111) and Pt(110) and two stepped surfaces of Pt(332) and Pt(331), were prepared and used in the study of electro-oxidation of ethylene glycol (EG). All of these Pt single crystal electrodes belong to the [1 0] zone of crystallography, and exhibit on their surface (111) symmetry sites or certain combinations of terraces of (111) symmetry with steps of (111) symmetry type. It has been found that as a result of a favourable steric matching of surface sites the Pt(110) electrode manifested a higher activity both for EG dissociative adsorption and oxidation than that of the Pt(111) electrode. The stepped surfaces of Pt(332) and Pt(331) operated with certain combinations of characteristics of Pt(111) and Pt(110). The best electrocatalytic properties have been obtained with a Pt(331) electrode, and this is attributed both to the configuration of the atomic arrangement and to the stability of this surface.In summary, the above results show that the performance of a given Pt single crystal electrode in EG oxidation at a potential below 1.0 V may be evaluated by three factors.

1. (1) The ability to resist self-poisoning (AB) which describes the difficulty of EG dissociative adsorption on the electrode surface.

2. (2) The activity for EG oxidation (AC). In considering that the threshold potential for EG oxidation on all electrodes is at 0.3 V and that the self-poisoning is encountered in PGPS, the activity for EG oxidation may be reasonably characterized by the intensity of the peak current acquired in NGPS near 0.6 V, which corresponds to the maximum current of EG oxidation on an activated (non-poisoned) surface of the electrode.

3. (3) The stability of activity during potential cycling (SA) between 0.05 and 1.0 V, which describes the resistance to the decrease of intensity of the EG oxidation current during voltammetric cycling.

For the two basal planes studied, the AB and SA of Pt(111) are higher than those of Pt(110), but its AC is much lower than that of Pt(110). These differences are clearly related to the surface atomic arrangement of the two electrodes. As has been discussed above, the surface of Pt(111) is atomically smooth and stable during voltammetric cycling. The surface of Pt(110) presents, however, atomic steps and is reconstructed under experimental conditions, i.e. certain steric configurations are encountered on the Pt(110) surface. The high AC and the low AB may be assigned to a favourite stereographic matching during EG adsorption and oxidation on Pt(110).The two electrodes with stepped surfaces, Pt(332) and Pt(331), contain different densities of (110) sites, which are formed on the border between terrace and step, as shown in Fig. 8. The AB of these two electrodes has been observed at a moderate range between that of Pt(111) and the AB of Pt(110). With a majority of (111) sites on its surface, the electrode of Pt(332) operates at a relatively higher AC than Pt(111) does, and its SA is not as good as that of Pt(111) but is much better than the SA of a Pt(110) electrode. In all cases the highest AC and SA are obtained with a Pt(331) electrode. It may be seen from the profile of a (331) plane (shown by the cross-section of A-A in Fig. 8) that all atoms on the top of the surface participated in forming (110) sites, and the atom on the step has two functions — one is to form a (110) site with an atom located in the terrace of second layer and the other is to form a (111) site in the terrace of the same layer. It has been mentioned in the above discussions that the Pt(110) electrode keeps a higher AC due to favourite stereographic matching in EG adsorption and oxidation, but its SA is the worst, due to the instability of the surface. The highest AC and SA obtained with Pt(331) may be ascribed not only to the high density of (110) sites existing on the surface, but also to the stabilization of these (110) sites, and moreover, the synergy generated by the atomic arrangement of the Pt(331) surface may also contribute to the performance of the Pt(331) electrode.     

C60固体中的相变

本文用（ｅｘｐ－６－１）势对固体Ｃ６０中分子间的相互作用进行计算，给出常温以下固体Ｃ６０中分子存在的状态，计算表明，常温下Ｃ６０高速旋转，随着温度降低，旋转速度逐渐减小，并且旋转轴向也逐渐趋于单一，当降到－２６０Ｋ时发生一级相变，此时ＦＣＣ晶胞中（０，０，０），１／２，１／２，０），（１，１／２，１／２）及（１／２，０，１／２）四套格点上的分子各只绕［１１１］三重轴旋转，Ｃ６０晶体从ＦＣＣ结构变为     

Electrochemical and FTIRS characterisation of NO adlayers on cyanide-modified Pt(111) electrodes: the mechanism of nitric oxide electroreduction on Pt

We report here a study, using cyclic voltammetry and FTIRS, of NO irreversibly adsorbed on a cyanide-modified Pt(111) electrode. NO adlayers were formed by immersion of the cyanide-modified Pt(111) electrode in an acidic solution of KNO(2). The behaviour of NO adsorbed on the cyanide-modified electrode is very similar to that of NO on the clean Pt(111) surface, suggesting that adsorbed cyanide (saturation coverage theta(CN) = 0.5) behaves simply as a third body, blocking some of the surface sites but leaving the free Pt sites unaffected. Comparison of the voltammetric profile for NO electroreduction on Pt(111) and on cyanide-modified Pt(111) electrodes has allowed us: (i) to confirm that the reduction of three-fold hollow NO and atop NO on Pt(111) electrodes occurs in two distinct reduction peaks, as previously proposed by Rosca et al. (Langmuir, 2005, 21, 1448); (ii) to suggest that the reduction of irreversibly adsorbed NO layers on Pt electrodes can proceed through two possible paths, one involving an EE mechanism in which the rate-determining step (rds) is an Eley-Rideal reaction, with a direct proton transfer from the solution to adsorbed NO, and the other involving an EC mechanism in which the rds is a Langmuir-Hinshelwood reaction of adsorbed NO with adsorbed H. The availability of adsorbed hydrogen determines which path is followed by the reaction; (iii) to identify the smallest atomic ensemble for the reduction of NO on Pt as being composed of two adjacent Pt atoms.     

利用给体-π-受体分子模板在Au(111)电极表面构筑富勒烯带状结构(英文)

富勒烯与功能分子之间的电荷作用已经被广泛应用于功能性器件的构筑中.这些功能器件的性能与电极表面的薄膜排布结构有着密切关系.因此,研究电极表面的富勒烯和功能分子的组装结构对这些器件的构筑和功能的发挥有着重要意义.本文利用电化学扫描隧道显微镜技术,在HClO4溶液中系统研究了C60分子与有机电子给体-π-受体分子C16H33O-I3CNQ[Z-β-(5-hexadecyloxy-1,3,3-trimethyl-2-indolium)-α-cyano-4-styryl dicyanomethanide]在Au(111)电极表面的二维组装结构.研究发现:C16H33O-I3CNQ分子在Au(111)电极表面组装形成具有短程有序性的条陇状结构;而C60分子在C16H33O-I3CNQ模板之上组装形成了带状结构.C60分子带状结构的形成方向受到了C16H33O-I3CNQ分子中电子给体-π-受体部分排列结构的影响.C60分子与C16H33O-I3CNQ分子之间的π-π堆积作用和电荷转移作用对这种带状结构的形成有着密切关系.这一结果为利用富勒烯和功能分子之间的作用构筑功能器件提供了一种新的制备方法.     

Selective electrocatalysis of acetaldehyde oxime reduction on (111) sites of platinum single crystal electrodes and nanoparticles surfaces

The reduction of acetaldehyde oxime (AO) in acid medium on platinum surfaces is a structure sensitive reaction that takes place almost exclusively on (111) sites of Pt electrodes, and it is strongly inhibited on Pt(100) and Pt(110) surfaces. A study using stepped electrodes with (111) terraces and monoatomic steps either with (100) and (110) orientation shows that the activity of the electrode is also dependent on the terrace width, i.e., the wider the terrace is, the higher current density is recorded and the more positive the peak potential for AO reduction appears. Moreover, in the electrodes with (100) step sites, the reduction process appears at more negative potential than the electrodes with (111) step sites. Nanoparticles with some preferential orientations were also tested for the AO reduction reaction to check the presence of (111) ordered domains on the nanoparticles surface. Dedicated to Teresa Iwasita on the occasion of her retirement and for her contributions to Electrochemistry.     

富勒烯系列配合物η2-C60[Ru(NO)(PPh3)]n的合成与光电性能

合成了一系列新的富勒烯钌配合物.通过元素分析、紫外-可见光谱、红外光谱、光电子能谱(XPS)和13C及31PNMR等多种手段对它们进行了表征.结果表明.该系列配合物分子内存在超共轭效应,共轭电子多.离域性好.通过光伏效应装置研究了它们的光电性能,结果显示该系列配合物具有良好的光电性能.