Pd(Ⅱ)、Zn(Ⅱ)、Cu(Ⅱ)、原卟啉的非有机溶剂液-固萃取分离

难溶于水的原卟啉在1.0%的吐温80水溶液中因氢键作用力变为可溶。研究了Pd(Ⅱ)、Zn(Ⅱ)、Cu(Ⅱ)、原卟啉在吐温80存在下的吸收光谱,并以原卟啉为萃取剂,考察了金属原卟啉在非有机溶剂液-固萃取体系中的分配行为,讨论了分相盐、成相聚合物、萃取剂、萃取酸度等对金属原卟啉在两相分配的影响。结果表明,(NH4)2SO4浓度1.51 mol/L,吐温80质量浓度9.0%,原卟啉浓度6.0×10-5mol/L,萃取酸度分别为5.0与pH 9.0,沸水浴加热15 min的条件下可分别实现Pd(Ⅱ)~Zn(Ⅱ),Cu(Ⅱ)~Pd(Ⅱ)的定量分离;体系萃取容量为0.020 mg/mL。该法不用有毒溶剂,仅控制萃取酸度分离性质相近的元素。其萃取机理是:金属原卟啉分子上的羰基质子受体与吐温分子上的羟基质子供体形成氢键。     

甲醛在Pd(111)与Pd(100)晶面上氧化的计算化学研究

使用密度泛函理论对甲醛分子在Pd(111)晶面与Pd(100)晶面的氧化反应机理进行研究,结果表明,Pd(100)晶面相比于Pd(111)晶面更有利于甲醛分子的氧化,为进一步合理设计甲醛氧化贵金属催化剂提供了理论依据。     

Zn(AA)2与Zn(MAA)2并用对EPDM硫化胶性能影响

本文研究了丙烯酸锌[Zn(AA)2]与甲基丙烯酸锌[Zn(MAA)2]并用对三元乙丙橡胶(EPDM)物理机械性能的影响。实验结果表明：Zn(AA）2与Zn(MAA)2并用对EPDM性能的影响不产生协同效应，Zn(AA)2对提高EPDM硫化胶物理力学性能和与金属的粘合强度比Zn(MAA)2有更显著的效果，Zn(AA)2的用量在4—5份时即可取得较好的粘合强度。     

废旧含钯催化剂Pd/α-Al_(2)O_(3)中Pd的环保高效提取

采用HCl+H_(2)O_(2)混合溶液浸泡废旧含钯催化剂Pd/α-Al_(2)O_(3),滤掉氧化铝球颗粒,在滤液中加入水合肼还原,形成Pd单质沉淀,过滤,加弱酸除去杂质,再过滤,滤饼在N_(2)保护下80℃烘干,得到高纯单质Pd。该方法成本低,相对于王水法更环保、高效,Pd回收率>99.99%,纯度>99.5%。     

Pd(OH)_2胶体预处理及化学镀法修补复合Pd膜

提出了一种有效的膜缺陷修补方法,即预先采用Pd(OH)2胶体浸渍有缺陷的Pd膜,还原后再化学镀金属Pd。通过扫描电镜(SEM)和金相显微镜对膜的表面和断面进行表征,并结合透氢性能测试对膜的修补效果进行了评价。研究结果表明:预处理后所形成的Pd金属微粒可富集在膜缺陷处且对后续的化学镀反应有良好的催化作用,从而促进了金属Pd在缺陷处的沉积,使膜缺陷得到有效修补。文中修补工艺可在几乎不损失氢通量的前提下大大提高Pd膜的选择性。     

Electrochemical Performance of Zn(002) and Zn(100) Single Crystals in 6.0mol·L~(-1) KOH

1 INTRODUCTION The zinc based batteries have high energy/power densities that compared with other alkaline batteries. Although these batteries are commercially available, the problems of the zinc electrode such as dendrite growth, shape change and high dissolution are not completely overcome. So far, many attempts have been undertaken to overcome these difficulties, but the problems still remain elusive[1―4]. The single crystal has definite atomic structure at the surface, so it has the …     

M-hexaferrite–APTES/Pd(0) Magnetically Recyclable Nano Catalysts (MRCs)

Magnetically recovable BaFe₁₂O₁₉–APTES–Pd(0) and SrFe₁₂O₁₉–APTES–Pd(0) catalysts were easily synthesized by immobilizing Pd nanoparticles on the surface of magnetic hexaferrite–NH₂ microspheres. It was found that the combination of BaFe₁₂O₁₉, SrFe₁₂O₁₉ and 3-aminopropyltriethoxysilane (APTES) could give rise to structurally stable catalytic sites. Furthermore, BaFe₁₂O₁₉–APTES–Pd(0) and SrFe₁₂O₁₉–APTES–Pd(0) magnetically recyclable nano catalysts (MRCs) can be recovered by magnet and reused for nine runs for hydrogenation of 4-nitroaniline and dinitribenzene without significant loss in its catalytic activity which shows the indicative of a potential applications of these catalyst in industry.     

New catalytic functions of Pd–Zn, Pd–Ga, Pd–In, Pt–Zn, Pt–Ga and Pt–In alloys in the conversions of methanol

Pd and Pt supported on ZnO, Ga₂O₃ and In₂O₃ exhibit high catalytic performance for the steam reforming of methanol, CH₃OH+H₂OCO₂+3HH₂, and the dehydrogenation of methanol to HCOOCH₃, 2CH₃OHHCOOCH₃+2HH₂. Combined results with temperature-programmed reduction (TPR) and XRD method revealed that Pd–Zn, Pd–Ga, Pd–In, Pt–Zn, Pt–Ga and Pt–In alloys were produced upon reduction. Over the catalysts having the alloy phase, the reactions proceeded selectively, whereas the catalysts having metallic phase exhibited poor selectivities.     

Pd(II)-Cu(II)催化氧化净化PH3的动力学实验

传统的净化方法难以实现低成本、高效、选择性净化含磷化氢尾气,这限制了含磷化氢尾气的资源化技术的实现.文章利用自主筛选的催化剂,在实验室进行了Pd2 浓度、Cu2 浓度、反应温度、混和气氧体积分数、磷化氢质量浓度、混合气流速等因素对Pd(II)-Cu(II)水溶液净化含磷化氢气体影响的研究.实验结果表明,Pd(II)-Cu(II)催化剂在低温(22-73 ℃)、常压下(100 kPa)对质量浓度为850 mg/m3磷化氢气体净化效率可高达100%.并且催化剂稳定性随催化氧化反应温度的升高而降低,随被净化混和气中氧体积分数、吸收液中Pd2 浓度及Cu2 浓度增大而增强;催化氧化净化效率随混和气中磷化氢质量浓度升高而降低,随被净化的混和气流速降低而升高.     

Pd(Ⅱ)-Cu(Ⅱ)催化氧化净化PH_3的动力学实验

传统的净化方法难以实现低成本、高效、选择性净化含磷化氢尾气,这限制了含磷化氢尾气的资源化技术的实现。文章利用自主筛选的催化剂,在实验室进行了Pd2+浓度、Cu2+浓度、反应温度、混和气氧体积分数、磷化氢质量浓度、混合气流速等因素对Pd(II)-Cu(II)水溶液净化含磷化氢气体影响的研究。实验结果表明,Pd(II)-Cu(II)催化剂在低温(22—73℃)、常压下(100 kPa)对质量浓度为850 mg/m3磷化氢气体净化效率可高达100%。并且催化剂稳定性随催化氧化反应温度的升高而降低,随被净化混和气中氧体积分数、吸收液中Pd2+浓度及Cu2+浓度增大而增强;催化氧化净化效率随混和气中磷化氢质量浓度升高而降低,随被净化的混和气流速降低而升高。     

仲辛基苯氧乙酸萃取Zn(II)的性能

研究了一种新型萃取剂仲辛基苯氧乙酸(CA–12)的皂化以及从盐酸介质中萃取Zn(II)的性能. 考察了萃取温度、平衡水相酸度、萃取剂浓度等因素对萃取的影响. 氨水皂化CA–12的最佳条件是使用含有1.0 mol/L NaCl的稀氨水制皂、皂化率为80%；分配比随平衡水相酸度的增加而减小，且lgD与pH呈线性关系，其斜率约为2；分配比随萃取剂初始浓度的增大而增大；初始酸度pH=6.0~6.5、萃取剂初始浓度CHA>0.10 mol/L时，水相中0.01 mol/L Zn(II)几乎被定量萃取. 计算得到了CA–12从盐酸介质中萃取Zn(II)的过程热效应DH=3.28 kJ/mol.     

Zn(Ⅱ)配合物合成及生物活性研究进展

综述了近年来Zn(Ⅱ)配合物的合成及生物活性研究,对发展前景作了展望。     

壳聚糖衍生物对Zn(Ⅱ)的吸附行为

引言 壳聚糖(CTS)是由甲壳素经脱乙酰基化反应而得到的一种天然高分子聚合物,由于具有独特的分子结构,良好的理化性能、药理作用及可降解和多种生物活性,其本身可用作医药保健品和药用辅料等,它还可借其结构中的羟基和氨基与金属离子配位形成有机金属配合物[1].     

New dinuclear Pd(II) complex with pyrazolate bridges. Synthesis and crystal structure of [Pd(μ-pz)(pzH)2]2(BF4)2 (pzH=pyrazole)

Dinuclear pyrazolate-bridged Pd(II) complex [Pd(μ-pz)(pzH)₂]₂(BF₄)₂ has been prepared by treatment of pyrazole (pzH), sodium ethoxide, and [Pd(CH₃CN)₄](BF₄)₂. The new complex has been characterised by elemental analyses, IR, ¹H NMR, ¹³C{¹H} NMR, and single crystal X-ray diffraction methods. This structure shows two palladium atoms bridged by two pyrazolate ligands. The square-planar geometry of each Pd atom is completed by two pyrazole ligands. The six-membered dipalladacycle formed by the two Pd atoms and the two bridging pyrazolate ligands adopt a distorted boat-like conformation. This compound is the first example of a dinuclear Pd(II)–pyrazolate homoleptic complex.     

巯基改性木薯秸秆吸附水体Cu(Ⅱ)和Zn(Ⅱ)特性

以废弃木薯秸秆为原料,经碱化、添加巯基官能团进行改性得到吸附剂,对其进行了表征,并研究了不同条件下吸附剂的对Cu(Ⅱ)和Zn(Ⅱ)吸附性能。结果表明,木薯秸秆成功引入巯基基团。经过巯基改性后的木薯秸秆的吸附量得到提升,吸附量随p H的升高而增大,在30 min内吸附量可迅速达到平衡,吸附动力学符合准2级动力学方程。对Cu(Ⅱ)的等温吸附符合Langmiur等温模型,近似于单层吸附,理论最高吸附量为65.36 mg/g;对Zn(Ⅱ)的等温吸附符合Freundlich等温模型,以多分子层吸附为主,理论最高吸附量为60.24 mg/g。两者吸附过程均为自发的放热过程。     

Mg(Zn)-Al(Fe)层状双氢氧化物磷酸根吸附性能研究

采用共沉淀法合成Mg-Al-LDH、Mg-Fe-LDH和Zn-Al-LDH三类不同的层状双金属氢氧化物,系统研究其磷酸根吸附行为和影响因素。结果表明,Mg-Al-LDH对于磷酸根的饱和吸附量可达99.17 mg/g,吸附过程符合Langmuir模型和准二级动力学模型,弱酸性环境和金属阳离子的存在有利于磷酸根的吸附,而阴离子的加入则会抑制磷酸根的吸附。磷酸根在Mg-Al-LDH表面的吸附是静电吸引、化学吸附和阴离子插层共同作用的结果。     

Mg(Zn)-Al(Fe)层状双氢氧化物磷酸根吸附性能研究

采用共沉淀法合成Mg-Al-LDH、Mg-Fe-LDH和Zn-Al-LDH三类不同的层状双金属氢氧化物,系统研究其磷酸根吸附行为和影响因素。结果表明,Mg-Al-LDH对于磷酸根的饱和吸附量可达99.17 mg/g,吸附过程符合Langmuir模型和准二级动力学模型,弱酸性环境和金属阳离子的存在有利于磷酸根的吸附,而阴离子的加入则会抑制磷酸根的吸附。磷酸根在Mg-Al-LDH表面的吸附是静电吸引、化学吸附和阴离子插层共同作用的结果。     

壳聚糖对痕量重金属Cu(Ⅱ)和Zn(Ⅱ)吸附作用的研究

研究了壳聚糖对Cu(Ⅱ)和Zn(Ⅱ)两种离子的吸附作用,探讨了外界因素pH、吸附时间和壳聚糖用量对吸附的影响,并确定最佳的吸附条件。     

Carbon–chlorine bond cleavage in chlorofluoroethanes on Pd(111)

The kinetics of carbon–chlorine bond cleavage on a Pd(111) surface have been investigated using several dichloroethanes with varying fluorine content (CF₃CFCl₂, CH₃CFCl₂, CH₂FCFCl₂, CH₃CHCl₂, CH₂ClCH₂Cl). Preliminary results show that the dechlorination rates in these molecules exhibit trends that are similar to those observed in catalytic hydrodechlorination over supported Pd catalysts. Fluorination of the 1,1‐dichloroethanes decreases the rate constant for dechlorination. The presence of only one chlorine atom on each carbon atom (CH₂ClCH₂Cl vs. CH₃CHCl₂) also reduces the rate constant for dechlorination. A Hammett correlation using field substituent parameters was established for the rate of dechlorination in an attempt to probe the nature of the transition state to carbon–chlorine bond cleavage ( ). The dechlorination rate constant for 1,1‐dichloroethanes is slightly reduced with increasing field effects (increasing fluorination) and the Hammett correlation reveals a reaction constant of ρ = -1.0 ± 0.2. The interpretation of this result is that there is little polarization of the C–Cl bond in the transition state for dechlorination, which is consistent with a transition state that is early in the reaction coordinate. This revised version was published online in July 2006 with corrections to the Cover Date.     

纳米Pd/P(AAEM-St)复合材料的制备与表征

超声引发乳液聚合制备了纳米钯/乙酰乙酸基甲基丙烯酸乙酯-苯乙烯共聚物[Pd/P(AAEM-St)]复合材料,研究了复合材料的结构及热稳定性。XRD结果表明Pd2+被还原成了Pd粒子,FTIR结果表明纳米粒子与聚合物基体之间存在相互作用,TG结果表明纳米粒子的存在对P(AAEM-St)基体的热稳定性有一定影响。