电沉积Ni–Ru合金及其结构和性能研究

在(25±2)°C下,从含有50g/LRuCl3·nH2O、30.0g/L乙酸钠、30.0g/L二水合柠檬酸钠和15.0~50.0g/LNiSO4·6H2O的溶液(pH3.0)中,以10~90mA/cm2在铜基底上电沉积制备了Ru含量为5%~70%(原子分数)的Ni–Ru合金。采用X射线衍射(XRD)、扫描电子显微镜(SEM)和电化学方法,研究了镀液中NiSO4质量浓度和电流密度对沉积层组成、表面形貌、结构及电催化析氢活性的影响。结果表明,溶液中Ru优先析出并能促进Ni的沉积,镀层中Ru含量随着镀液中Ni2 质量浓度的提高而降低,低电流密度有利于获得Ru含量高的镀层。随着镀液中Ni2 质量浓度的降低或电流密度的提高,镀层表面形貌由较为平整、均匀变为多孔的颗粒状。镀层主要呈现面心立方Ni结构特征,且晶粒尺寸随镀层中Ru含量的增加而变小。Ni–Ru合金电极的析氢活性优于纯Ni,当镀层的Ru原子分数超过15%时,其析氢活性与纯Ru电极接近。     

金属阳极涂层中Ru,Sn,Ir,Pt,Pd报X光荧光快速定量测定

本文在阐明计算机模拟与专家系统基本概念的基础上，着重综述了国内外关于棉花的生育期、叶龄、不合与呼吸作用等６个方面的模拟模型，提出了现有模型存在的问题以及今后的发展方向与前景。     

One-step preparation of Pt–M@FP-MWNT catalysts (M = Ru,Ni, Co,Sn, and Au) by γ-ray irradiation and their catalytic efficiency for CO and MeOH

Pt–M@FP-MWNT catalysts (M = Ru, Ni, Co, Sn, and Au) were prepared by one-step γ-ray irradiation. Two different types of functional polymers (FP), such as poly(vinylphenyl boronic acid) (PVPBAc) and poly(vinylpyrorridone) (PVP), were used as anchoring agents, when Pt–M nanoparticles were deposited on the multi-walled carbon nanotube (MWNT) using γ-ray irradiation in aqueous solution at room temperature. The obtained Pt–M@FP-MWNT catalysts were then characterized by XRD, TEM, and elemental analysis. The catalytic efficiency of the Pt–M@FP-MWNT catalysts was examined for CO stripping and MeOH oxidation for use in a direct methanol fuel cell (DMFC). The catalytic efficiency of the Pt–M@FP-MWNT catalyst for MeOH oxidation follows this order: Pt–Sn@FP-MWNT > Pt–Co@FP-MWNT > Pt–Ru@FP-MWNT > Pt–Au@FP-MWNT > Pt–Ni@FP-MWNT catalysts. The CO adsorption capacity of the Pt–M@FP-MWNT catalyst for CO stripping is as follows: Pt–Ru@FP-MWNT > Pt–Sn@FP-MWNT > Pt–Au@FP-MWNT > Pt–Co@FP-MWNT > Pt–Ni@FP-MWNT catalyst.     

Biobutanol Dehydrogenation to Butyraldehyde over Cu,Ru and Ru–Cu Supported Catalysts. Noble Metal Addition and Different Support Effects

Abstract  

n-Butanol dehydrogenation to butyraldehyde was studied using Ru, Cu and Ru–Cu catalysts supported on ceria, titania and zirconia. Among the monometallic Cu and Ru supported catalysts, the non-noble catalytic systems recorded higher conversions and butyraldehyde selectivities than the noble catalysts. Furthermore, the 5Cu/ZrO₂ catalyst had the best catalytic activity and selectivity. This behaviour is related to the good metal phase dispersion on the zirconia structure. The addition of Ru reduced this catalyst’s performance because Ru incorporation weakened the Cu-support interaction and favoured the sintering of the Cu metal crystallites.     

Ni—Fe—P,Ni—W—P合金与镀层性能

本文通过研究非晶态Ｎｉ－Ｐ合金电镀体系加入少量Ｆｅ、Ｗ等元素对镀层性能的影响,发现非晶态Ｎｉ－Ｐ合金镀层中引入少量Ｆｅ、Ｗ元素后既能保持镀层优良的耐蚀性又可大大提高镀层的硬度和耐磨性。     

Preparation,characterization, and kinetic evaluation of dendrimer-derived bimetallic Pt–Ru/SiO2 catalysts

A series of silica-supported Pt, Ru, and Pt–Ru catalysts has been synthesized using dendrimer–metal nanocomposite (DMN) precursors prepared by both co- and sequential complexation with metal salts. The catalysts have been characterized by several techniques, including electron microscopy, temperature-programmed titration of adsorbed oxygen, and X-ray diffraction. Liquid-phase selective hydrogenation of 3,4-epoxy-1-butene (EpB) was used as a probe reaction to evaluate their catalytic performance. The bimetallic catalyst prepared by the co-complexation method exhibits a superior catalytic activity compared to the sequential one, and is much more active than a conventional catalyst prepared by incipient wetness. The activity enhancement is attributed to a bifunctional performance of the PtRu alloy sites created, based on a strong correlation between turnover frequencies, and both the alloy compositions and metal surface site distributions. In addition, the co-complexation catalyst is selective toward crotonaldehyde, suggesting that this reaction pathway is favored on the PtRu sites.     

Electrocatalytic characteristics of Pt–Ru–Co and Pt–Ru–Ni based on covalently cross-linked sulfonated poly(ether ether ketone)/heteropolyacids composite membranes for water electrolysis

Membrane electrode assemblies (MEAs) of covalently cross-linked sulfonated poly(ether ether ketone) (CL-SPEEK)/heteropolyacids (HPAs) composite polymer with platinum-based alloys such as Pt–Ru–Co and Pt–Ru–Ni were prepared and their electrochemical properties for water electrolysis were investigated. The HPAs, which were used in the composite membranes, were tungstophosphoric acid (TPA) (the part of TPA data was permitted by the previous authors), molybdophosphoric acid (MoPA), and tungstosilicic acid (TSiA). The MEAs with Pt–Co, Pt–Ru–Co, and Pt–Ru–Ni in the anode catalyst layer were prepared by means of a non-equilibrium impregnation–reduction (I–R) method. The electrocatalytic properties of composite membranes, such as the cell voltage and coulombic charge in CV, were in the following order: CL-SPEEK/MoPA40 > CL-SPEEK/TPA30 > CL-SPEEK/TSiA40 (wt%). For the optimum cell applications of water electrolysis, the cell voltage of Pt/PEM/Pt–Ru–Co (Electrodeposited (Dep)-MoPA) MEA with a CL-SPEEK/MoPA40 membrane was 1.70 V at 80 °C and 1 A cm^?2, and this voltage carried a value lower than that of 1.81 V of Nafion 117. In addition, the observed activity of Pt–Ru–Co (75:12:13 by EDX) is a little higher than that of Pt–Ru–Ni (79:10:11 by EDX). The mean coulombic charge and activity enhancement of Pt–Ru–Co catalysts, with and without electrodeposition, showed the same CV profiles of the Pt–Ru–Co catalysts and were in the following order: Nafion 117 < CL-SPEEK/TSiA40 < CL-SPEEK/TPA30 < CL-SPEEK/MoPA40. The current density peak of electrodeposited electrodes was a little better than those of inactivated electrodes on the same membranes. The current peak by Pt–Ru–Co with CL-SPEEK/MoPA40 (Dep-MoPA) is more than about three times as high as those of Pt electrodes on the same membranes.     

Electroless deposited Ni–Re–P, Ni–W–P and Ni–Re–W–P alloys

Coatings of electroless Ni–W–P, Ni–Re–P and Ni–W–Re–P alloys were plated in alkaline citrate baths containing amino alcohols, but not free ammonia ions. The reference Ni–P alloy was used as an intermediate layer in the sandwich: Ni–Me–P/Ni–P/substrate. An extremely homogeneous thickness distribution of all alloy components was found by applying scanning Auger electron spectroscopy (SAES(. The inclusion of refractory metals at the expense of nickel and without substantial change in phosphorus content was established. A non-oxidized state of the codeposited Re and W in Ni–W–P, Ni–Re–P and Ni–W–Re–P alloys was determined by means of X-ray photoelectron spectroscopy examination, as well as by SAES profiles, revealing the absence of oxygen throughout the coatings. All alloy films are amorphous and paramagnetic.     

H2 and H2/CO oxidation mechanism on Pt/C, Ru/C and Pt–Ru/C electrocatalysts

The oxidation kinetics of H₂ and H₂ + 100 ppm CO were investigated on Pt, Ru and Pt–Ru electrocatalysts supported on a high-surface area carbon powder. The atomic ratios of Pt to Ru were 3, 1 and 0.33. XRD, TEM, EDS and XPS were used to characterize the electrocatalysts. When alloyed with ruthenium, a decrease in mean particle size and a modification of the platinum electronic structure were identified. Impedance measurements in H₂SO₄, at open circuit potential, indicated different mechanisms for hydrogen oxidation on Pt/C (Tafel–Volmer path) and Pt–Ru/C (Heyrowsky–Volmer path). These mechanisms also occur in the presence of CO. Best performances, both in H₂ and H₂ + CO, were achieved by the catalyst with the ratio Pt/Ru = 1. This is due to a compromise between the number of free sites and the presence of adsorbed water on the catalyst. For CO tolerance, an intrinsic mechanism not involving CO electroxidation was proposed. This mechanism derives from changes in the electronic structure of platinum when alloyed with ruthenium.     

Ru(II)–CO complexes of thioarylazoimidazoles: Syntheses,structures, spectroscopy and DFT calculation

The complexes, cis-(CO)-trans-(Cl)-[Ru(SRaaiNR)(CO)₂Cl₂] (2) and trans-(Cl)-[Ru(SRaaiNR)(CO)Cl₂] (3) (SRaaiNR = 1-alkyl-2-{(o-thioalkyl)phenylazo}imidazoles; R = Me (1a) and Et (1b)) have been synthesized and characterized. The structural confirmation is achieved by single crystal X-ray structure determinations. The complexes show Ru(III)/Ru(II) couple and ligand reductions. Electronic structure and spectral properties of the complexes have been explained with the DFT and TDDFT calculation.     

Ru改性Ni/Ce_(0.8)Pr_(0.2)O_2催化剂用于乙醇水蒸气重整制氢研究

利用柠檬酸溶胶-凝胶法制备Ru改性的Ni/Ce_(0.8)Pr_(0.2)O_2催化剂,并通过乙醇水蒸气重整反应考察了催化剂的活性及稳定性。探究了Ru改性对Ni/Ce_(0.8)Pr_(0.2)O_2催化剂催化乙醇水蒸气重整制氢的活性及稳定性的影响。通过X射线衍射、氮气吸附脱附、H2-程序升温还原等手段对催化剂结构及性质进行表征。结果表明,Ru的加入有助于降低NiO的还原温度,NiO与Ru作用紧密,因而Ru具有提高催化剂活性及稳定性的作用。在600℃、水与乙醇摩尔比为4、乙醇气相空速为69 900m L/gcat·h时,Ru改性的Ni/Ce_(0.8)Pr_(0.2)O_2催化剂具有较高的乙醇转化率且能得到较好的甲烷及CO_2气相产率。     

ZnS:Cu,Ni热敏型发光体的研制

本文给出了ZnS：Cu，Ni热敏型发光体的制备工艺和各种性能参数。论述了ZBS；Cu，Ni热敏型发光体的发光机理。     

掺Cr,Ni钛酸钡陶瓷的介质非线性效应

对ＢａＴｉＯ３及其掺Ｃｒ或Ｎｉ陶瓷的ε，ｔｇδ进行了测量和讨论。测量电压为０．０５－５Ｖ，测量频率为０．１－１００ｋＨｚ，实验表明：ＢａＴｉＯ３陶瓷是非线性材料，适量掺入Ｃｒ或Ｎｉ可明显抑制这种效应。非线性效应、内偏置电场现象和老化现象都邮自同一根源，即电畴结构的稳定性，非线性效应是电畴结构反抗外场作用稳定性的表现。     

[P_4MP_4]~(n-)(M=Fe,Ru,Os,Co,Rh,Ir;n=1,2)和[P_4MP_4Na]~-(M=Fe,Ru,Os)的结构和稳定性

用密度泛函理论(DFT)研究了标题化合物的电子结构、电离能和稳定性。研究发现,体系的交错型(D4d)结构是稳定的,而重叠型(D4h)异构体则是过渡态。从垂直电离能的计算可知,Fe、Ru和Os的配合物对分子内的库仑排斥力而言是不稳定的,而Co、Rh和Ir的类似物则是稳定的。此外,计算结果表明,钠能作为抗衡离子来抵消分子内的库仑排斥力,使电子不会自发地离去,因为这样可以产生更稳定的结构,即[P4MP4Na]-,从而可以便于实验操作。另外,金属-配体裂解反应能的计算表明这些夹心型配合物都是热稳定的。     

Comparative Study on Partial Oxidation of Methane over Ni/ZrO2, Ni/CeO2 and Ni/Ce–ZrO2 Catalysts

The partial oxidation of methane has been studied by sequential pulse experiments with CH₄ O₂ CH₄ and simultaneous pulse reaction of CH₄/O₂ (2/1) over Ni/CeO₂, Ni/ZrO₂ and Ni/Ce–ZrO₂ catalysts. Over Ni/CeO₂, CH₄ dissociates on Ni and the resultant carbon species quickly migrate to the interface of Ni–CeO₂, and then react with lattice oxygen of CeO₂ to form CO. A synergistic effect between Ni and CeO₂ support contributes to CH₄ conversion. Over Ni/ZrO₂, CH₄ and O₂ are activated on the surface of metallic Ni, and then adsorbed carbon reacts with adsorbed oxygen to produce CO, which is composed of the main path for the partial oxidation of methane. The addition of ceria to zirconia enhances CH₄ dissociation and improves the carbon storage capacity. Moreover, it increases the storage capacity and mobility of oxygen in the catalyst, thus promoting carbon elimination.     

含Ru多元涂层的研究

金属阳极涂层的发展趋势是多元涂层。以图表的形式比较了多元涂层阳极的电化性能优于ＲｕＴｉ二元体系的阳极。     

Fe,Co,Ni改性SAPO-34分子筛上MTO反应的理论研究

为明确分子筛对MTO反应的催化活性和产物选择性的影响,采用色散力矫正的密度泛函理论方法,以SAPO-34分子筛为催化剂,考察了3种不同金属Fe、Co和Ni改性的SAPO-34分子筛布朗斯特(Brnsted,B酸)酸强度的变化,并研究不同酸性的催化剂对甲醇制烯烃(MTO)反应中的低碳烯烃催化活性和选择性的影响及2者间的关联。通过计算去质子化能比较改性前、后SAPO-34分子筛的酸性强度变化,酸性强度顺序为Fe APO-34Co APO-34SAPO-34Ni APO-34。通过计算MTO反应克服的反应能垒,比较低碳烯烃的催化活性和选择性,Fe、Co、Ni金属改性的SAPO-34分子筛对乙烯生成反应的催化活性顺序为Fe APO-34≈Ni APO-34Co APO-34;对丙烯生成反应的催化活性顺序为Fe APO-34≈Co APO-34Ni APO-34;Ni原子的引入比Fe、Co原子的引入提高了乙烯的选择性,而Fe、Co原子的引入比Ni原子的引入提高了丙烯的选择性。     

Al,Ni掺杂ZnO的电子结构与光学性质

利用基于密度泛函理论的第一性原理方法计算了纯ZnO和分别掺摩尔分数均为6.25%Al,Ni的ZnO的能带结构、电子态密度分布及光学性质。计算结果表明:ZnO掺杂Al,Ni后,其Fermi面均上移并进入导带;Zn0.9375Ni0.0625O的能带结构在导带底附近出现了4条杂质带。纯ZnO,Zn0.9375Al0.0625O和Zn0.9375Ni0.0625O的光学性质在低能处有较大的差异,其中Zn0.9375Al0.0625O在可见光区的吸收系数和反射率较之另外两种材料都相对较低,但三者的光学性质在高能处却非常相似。Zn0.9375Al0.0625O的吸收边有蓝移的趋势,而Zn0.9375Ni0.0625O的吸收边红移。掺杂Ni对ZnO的吸收系数等光学性质的改变更为明显。     

Methanation of carbon dioxide over mesoporous Ni–Fe–Ru–Al2O3 xerogel catalysts: Effect of ruthenium content

Mesoporous nickel (35 wt%)–iron (5 wt%)–ruthenium (x wt%)–alumina xerogel (denoted as 35Ni5FexRuAX) catalysts with different ruthenium contents (x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0) were prepared by a single-step sol–gel method for use in the methane production from CO₂ and H₂. Conversion of CO₂, yield for CH₄, metal surface area, and the amount of desorbed carbon dioxide of the catalysts showed volcano-shaped trends with respect to ruthenium content. Experimental results revealed that metal surface area and the amount of desorbed carbon dioxide of 35Ni5FexRu catalysts were well correlated with conversion of CO₂ and yield for CH₄.