“超浓盐酸”介质中钯微乳萃取行为

采用多种分子谱学的表征手段, 研究了萃钯有机相中由于酸的共萃导致溶液微观聚集态结构的变化. 研究结果表明, 与高酸度盐酸水溶液平衡后的TBP载钯有机相微乳水团中形成了浓度远大于常规饱和浓盐酸的“超浓盐酸”; 微乳水团内H+和Cl-的大量聚集增浓对Pd离子的络合配位状态产生影响, H+参与了Pd离子配位状态的转变; 有机相“超浓盐酸”形成后, 使得微乳水团中大量存在的H+有可能参与调控水团中各种HmPdClnz+络合离子配位状态的相对含量. 被H+活化的TBP表面活性剂与钯离子的各种配位状态的匹配程度最终决定了钯的萃取行为.     

N_(235)萃取HCl体系中TBP消除第三相的作用机理

通过测定萃取有机相的电导率变化研究叔胺N235(三烷基胺)萃取盐酸体系中第三相的形成及改性剂消除第三相的作用机理。实验结果表明,无改性剂时萃取体系在各种条件下均出现第三相。第三相组成为R3NH (H2O)3·Cl-,具有导电性。加改性剂TBP(磷酸三丁酯)后,第三相消失。本文认为改性剂TBP消除第三相的作用机理是TBP能够将萃合物R3NH (H2O)3·Cl-拆分为可溶于惰性稀释剂的R3NH (H2O)3·O=P(OC4H9)3大阳离子,Cl-离子则以抗衡离子分散于稀释剂中。     

n型碲化镉单晶光电化学电池的研究II:金属离子修饰与光电化学催化

n-CdTe单晶表面用H2PtCl6或RuCl3溶液浸渍,显著提高了电池的效率及稳定性.除选择金属离子种类外,电极预处理及浸渍时间对修饰作用也有很大影响.固体表面分析表明,在PtCl6^2^-溶液中短时间浸渍的电极表面上有大量铂岛,能减少表面缺陷并催化界面反应.在RuCl3溶液中浸渍,将可使Ru^3^+离子吸附于电极表面,有利于光电化学反应.PdCl2溶液浸渍或长时间PtCl6^2^-溶液处理均得到不利的结果.     

Pt在多晶Au微盘电极上电沉积成核与晶体生长

于不同H2PtCl6浓度和超电势下,应用Fleischmann的电结晶成核及晶体生长模型和Barradas Bosco的电化学成相吸附成核模型,拟合多晶Au微盘电极( =30μm)上电沉积Pt的恒电势阶跃电流暂态曲线.得出:在稀H2PtCl6溶液中,上述沉积过程初期,发生H2PtCl6吸附并遵循二维瞬时成核与圆柱形生长模型.二维生长速率常数随超电势线性增加.跟随其后的是核的层状生长,其速率常数随超电势呈非线性变化.而在高浓H2PtCl溶液中,沉积机理转变为H2PtCl6的吸附、瞬时成核及三维正圆锥形的生长模式.其晶核的垂直生长速率常数kPERP比水平生长速率常数kPARA大两个数量级以上.况且,logkPERP随超电势线性增加,而logkPARA则随超电势呈反S形变化的关系.相同超电势下,无论kPERP还是kPARA,均比稀H2PtCl6溶液中的二维层状生长速率常数大几个数量级.     

N235萃取HCl体系中TBP消除第三相的作用机理

通过测定萃取有机相的电导率变化研究叔胺N₂₃₅(三烷基胺)萃取盐酸体系中第三相的形成及改性剂消除第三相的作用机理。实验结果表明，无改性剂时萃取体系在各种条件下均出现第三相。第三相组成为R₃NH⁺(H₂O)₃·Cl^-，具有导电性。加改性剂TBP(磷酸三丁酯)后，第三相消失。本文认为改性剂TBP消除第三相的作用机理是TBP能够将萃合物R₃NH+(H₂O)₃·Cl^-拆分为可溶于惰性稀释剂的R₃NH⁺(H₂O)₃·O=P(OC₄H₉)₃大阳离子，Cl^-离子则以抗衡离子分散于稀释剂中。     

皂化酸性磷酸酯萃取稀土离子过程中有机相的FTIR光谱表征

研究了不同浓碱皂化的Ｄ２ＥＨＰＡ－正庚烷体系萃取－系列稀土离子（Ｌａ＾３＋－Ｌｕ＾３＋）放射性的Ｐｍ除外）过程中有机相的ＦＴＩＲ光谱变化规律，结果说明，Ｄ２ＥＨＰＡ萃取稀土离子后，Ｐ－Ｏ基团５的红外吸收频率降低，吸收强度升高，说明Ｐ－Ｏ基团与稀土离子发生配位；红外光谱研究研究结果表明：不同稀土离子与Ｐ－Ｏ配位能力有差别，从Ｌａ＾３＋－Ｓｍ＾３＋ｓｇｎ ｗｕｇ ｃｅｌｔｗｙｅ ｕｑｗ ｆｕｌｊｅ ｓ     

Pt/SiO2-Al2O3催化剂中铂含量测定的方法

应用分光光度法测定了 Pt/SiO,2-Al,2O,3 催化剂中铂量,试样溶于氢氟酸、盐酸、磷酸及过氧化氢中,在1.2 mol·L-1盐酸溶液中高价铂的氯化物铬阴离子(PtCl2-,6)被氯化亚锡溶液还原生成呈黄色的亚氯铂酸(H,2PtCl,4);其吸收峰位于 403 nm 波长处,摩尔吸光率为 4.59×104L·mol-1·cm-1,遵守比耳定律的范围在0～10 mg/100 mL 之间.应用此方法分析了 4 件催化剂样品,每件样品测定9次,所求得测定结果的相对标准偏差均小于4%,标准加入回收率在101%～106%之间,取其中两件试样用X射线荧光光谱分析,取得了一致的结果.     

络合法除P507-N235体系中铁的研究

因铁离子具有强烈的水解倾向及易与其他离子形成配合物的性质,在溶剂萃取体系中的存在形式极为复杂。在稀土萃取体系中,采用P204或N235除铁,经盐酸反萃后,有机相中铁的反萃率较低,不能深度除去,影响萃取剂的萃取性能。而在P507-N235盐酸萃取体系中,Fe3+在低酸度下可被P507萃取,在高酸度下形成Fe Cl-4配合物被N235萃取,萃取率达99%以上,且难被反萃下来。研究采用草酸和EDTA络合法除去有机相中的铁,结果表明:草酸络合法除铁率较低,较难用草酸络合法将有机相中的铁反萃下来;在温度25℃、反萃时间14 min,相比1∶1的条件下,用EDTA络合法除铁,铁的反萃率可达97.51%,经4次错流反萃后,可将有机相中铁的浓度降至0.002 g·L-1,达到深度除铁的目的。     

双（十二烷基亚磺酰）乙烷溶剂萃取钯及其机理的研究

本文研究用双（十二烷基亚磺酰）乙烷萃取钯的性能，在ＫＩ存在下从７ｍｏｌ／Ｌ盐酸介质中用含有ＢＤＳＥ的氯仿能定量萃取钯，有机的钯可被硫脲或氨溶液反萃继之用ＴＭＫ－ＴｒｉｔｏｎＸ－１００光度法测定，研究了萃取的最佳条件及干扰情况，斜率法测得萃合物组成为Ｐｄ：Ｉ：ＢＤＳＥ＝１：２：１，红外光谱证实萃合物中ＢＤＳＥ的二个亚砜以硫原子与钯配位，萃合物为异位体络合物，提出了选择性萃取分离钯的新方法。     

酸性磷萃取剂在皂化过程中的结构变化与萃合物的组成

本文研究了酸性磷酸酯(D2EHPA等)皂化过程和萃取前后有机相结构的变化,证实了酸性磷酸酯萃取剂在皂化过程中生成微乳状液,进一步阐明萃取稀土离子时,在微乳状液的油水界面上发生离子交换反应,生成具有螫合型结构的萃合物,同时伴随着有机相中微乳状液的破乳过程。在用完全皂化的D2EHPA-仲辛醇-煤油溶液萃取二价离子时,得到萃取有机相中苹合物的组成为MA²,而不是通常认为的MA₂·2HA,从而可以提高萃取容量。     

Formation of super-concentrated hydrochloric acid in the third phase in tertiary amine N235-PtCl 6 2− -HCl system and its influences on the Pt microemulsion extraction

In this paper, we have investigated the formation of the third-phase in tertiary amine (N235)-PtCl ₆ ^2? -HCl system and the microscopic phase structural evolution of platinum-loaded organic phases before and after the occurrence of the third-phase. The third-phase is characterized by various spectroscopic techniques, and the small angle X-ray scattering (SAXS) experiments demonstrate the appearance of nano-aggregates, i.e., water-in-oil reversed micelles, in the third phase. The experimental results indicate that (1) formation of the third phase is related to the aggregation behaviors of nano-reversed micelles in which a super-concentrated hydrochloric acid formed with the H⁺ to H₂O molar ratio being much higher than that of the conventional 37 wt% saturated hydrochloric acid. (2) The occurrence of the super-concentrated HCl results in a great amount of H⁺ and Cl^? ions enriched and confined within the nano-water pools of W/O reversed micelles in third phase. Therefore, the coordination behaviors of platinum complex ions in that super-concentrated hydrochloric acid are very different from their corresponding behaviors in bulk aqueous solutions. It is possible that H⁺ ions participate in the formation of such complexes as H _m PtCl ₆ ^z+ in the super-concentrated hydrochloric acid. (3) The relative contents of various H _m PtCl ₆ ^z+ complexes are different corresponding to the H⁺ ion concentrations in confined nano-water pools. The association ability of the acidified tertiary amine N235 molecules (R₃NH⁺) with various H _m PtCl ₆ ^z+ complexes plays an important role in affecting the platinum extraction behaviors.     

钠离子取代对气相分子氢氘交换反应的影响

用质谱学方法测定分子的氢氘交换反应过程和结果是研究蛋白质分子等生物体系的分子构象,如蛋白质折叠状态的常用方法之一．本文利用线型离子阱．飞行时间质谱技术,在气相中测定了由不同个数钠离子所取代的简单多肽分子——五联丙氨酸（5Ala-nH＋nNa）．H^＋,,n=2,3,4,5的氢氘交换反应情况,得到了由不同个数钠离子取代的分子离子的氢氘交换反应速度以及交换的氢氘数量等,并研究了钠离子个数对分子氢氘交换反应的影响．结果表明,在本工作的实验条件下,钠离子的取代将影响分子离子的氢氚交换反应．当钠离子数为2时,（5Ala-2H＋2Na）．H^＋分子离子很难发生氢氘交换反应;当钠离子数增加时,对于（5Ala-3H＋3Na）．H^＋,（5Ala-4H＋4Na）．H^＋,和（5Ala-5H＋5Na）．H^＋等,分子的氢氘交换反应速度会加快．这可能是由于钠离子的取代导致了分子离子的构型以及分子的质子亲和势发生了显著的改变,因此影响它们的氢氘交换反应．此外,我们还研究了线型四极场的q值对离子氢氘交换反应的影响,发现对于某种离子,当其对应的四极场q值低于0．8时,对各种离子的交换反应速度影响不大,但当q值接近第一稳定区图的边界点,即当q接近0．908时,对某些离子的交换反应速度影响很明显．q值对离子的交换反应速度影响可以用离子的运动速度加快而导致碰撞反应能量增加来解释．     

脂肪胺水溶液吸收CO2的热力学参数的密度泛函理论研究

采用密度泛函理论研究CO2在脂肪胺水溶液热力学参数．研究的脂肪胺包括烷基胺、链烷醇胺、二胺以及氨基酰胺．在B3LYP/6-311＋ G（d,p）水平计算脂肪胺在CO2气相中的振动频率．通过连续介质模型在HF/6-31G（d）水平计算了溶剂几何优化的标准自由能,评价了CO2吸收到脂肪胺水溶液过程有关的两个重要参数：酸解离常数和标准焓变二者之间大致呈线性关系．随着胺碱度的提高,CO2吸收过程释放的热量增加,则胺再生所需的能量增加．     

FIA-FAAS system including on-line solid phase extraction for the determination of palladium, platinum and rhodium in alloys and ores

A number of aliphatic mono- and triamines have been investigated as potential reagents for solid phase extraction of Rh, Pd and Pt. Platinum group metals are recovered from hydrochloric acid solutions as ionic associates of their chloride complexes with protonated amines. The recovery of metals depends both on hydrophobic properties of amine and sorbent and on sorption behaviour of amine itself. For on-line solid phase extraction of platinum group metals 4-(n-octyl)diethylenetriamine and hyper cross-linked polystyrene sorbent SSPS have been applied. Quantitative recovery of rhodium and platinum in the form of their hexachloride complexes was achieved under non-equilibrium conditions of on-line dilution. Metals recovered are quantitatively eluted with 1 M hydrochloric acid solution in ethanol. A new FIA-FAAS method for the determination of Rh, Pd and Pt in solutions based on the decomposition of ores and alloys has been proposed. The RSD values are 0.03-0.08 at 50-ppb concentration level. The detection limits are 3-8 ppb for 1 min of preconcentration. The accuracy of the procedure was verified by the analysis of standard reference materials of sulfide ores and alloys.     

Propiconazole and Penconazole as Effective Extractants for Selective recovery and concentration of platinum(IV) and palladium(II) from hydrochloric acid solutions formed in leaching of spent aluminoplatinum and aluminopalladium catalysts

Selective recovery and concentration of platinum(IV) and palladium(II) from hydrochloric acid solutions of varied composition was studied using commercial reagents propiconazole and penconazole as extractants. The ranges of hydrochloric acid concentrations for effective extraction and highly selective separation of platinum metals from Al(III) and Ni(II) with propiconazole (toluene with 15 vol % n-decanol as deluent) and penconazole (chloroform) were determined. The conditions for 10-fold selective concentration of platinum metals with recovery of more than 99.9% of metal ions into the organic phase were found. The conditions for quantitative (>99%) stripping of platinum(IV) with a hydrochloric acid solution of thiourea and palladium(II) with ammonia solution were determined. The results obtained can be used for optimizing the modes of selective recovery of platinum(IV) and palladium(II) from hydrochloric acid solutions formed in leaching of alumina-supported platinum-rhenium, platinum-nickel, and palladium catalysts.     

4-(5-nonyl)pyridine extraction of platinum from different aqueous solutions

The partition of tracer-level (<10^?7 mole/l) platinum between various 4-(5-nonyl)-pyridine phases and aqueous nitric, hydrochloric, and sulphuric acid phases has been studied radiometrically as a function of the amine and acid concentrations. The effects of saltingout agents and some anions on the extraction of the metal are reported. The extraction data is compared with that of gold and conditions are established for the separation of daughter¹⁹⁹Au from neutron irradiated platinum. The distribution coefficients of various metal ions are given for the 4-(5-nonyl)pyridine-10M HCl system and their factors for separation from platinum estimated.     

Adsorption behavior of VII group elements on tertiary pyridine resin in hydrochloric acid solution

We investigated the adsorption behaviors of technetium and rhenium on tertiary pyridine resin in hydrochloric acid solution. Technetium has a little larger distribution coefficient in higher concentration of hydrochloric acid region than rhenium. However, the tendency of adsorption behavior of technetium and rhenium is similar. We concluded that the rhenium can be used as the substitute for technetium. Adsorption behaviors of platinum group elements were also investigated. The separation of technetium from platinum group elements is discussed.     

Tri-n-octylphosphine sulfide: : A selective organic extractant

Tri-n-octylphosphine sulfide (TOPS) has been investigated as the stationary phase in reversed-phase partition paper Chromatographie separations using nitric or hydrochloric acids as the mobile phase. TOPS has also been studied as an extractant for metal ions. Silver, mercury (II), and palladium (II) were found to have RF values of zero when nitric acid was used as the mobile phase. These same ions were also selectively extracted from aqueous nitric acid solutions. Gold(III), mercury(II), palladium (II), and platinum (IV) were found to have RF values of zero when hydrochloric acid was used as the mobile phase. However, only gold(III) and mercury(II) were extracted from aqueous hydrochloric acid solutions in liquid-liquid extraction systems. Several separations were successfully performed from 1 M nitric acid.