Investigation of electrochemical reactions on copper electrode in Cu4RbCl3I2 solid electrolyte

Investigations are carried out by potentiostatic method. It is found that at potentials ϕ less than 100 mV, a reaction rate of copper deposition is limited by the formation and the three-dimensional growth of copper nuclei and the rate of copper dissolution is limited by a two-dimensional growth of holes in the metal. The rate of nucleus growth was evaluated at 10⁻⁹...10⁻⁶ μm s⁻¹ depending on the potential. At ϕ>120 mV, the reaction rate is limited by charge transport at the exchange current density of 2.7 mA cm⁻² and the anodic transfer coefficient α_a≈ 0.45. The accumulation of a divalent copper phase on Cu/Cu₄RbCl₃I₂ interface at anodic polarization is explained by a parallel course of Cu⁺ − e → Cu²⁺ reaction.     

Kinetic and mechanistic study of the quasiliving cationic polymerization of styrene with the 2-phenyl-2-propanol/AlCl3 · OBu2 initiating system

The cationic polymerization of styrene with the 2-phenyl-2-propanol (CumOH)/AlCl₃ · OBu₂ initiating system at various dibutyl ether concentrations in a mixture of 1,2-dichloroethane and n-hexane (55:45 v/v) at −15 °C was investigated. The experimental results showed that an increase in dibutyl ether concentration leads to a noticeable decrease in the polymerization rate as well as to the more controlled polymerization in terms of molecular weight (M_n) and molecular weight distribution (MWD) evolutions. The kinetic investigation revealed that the polymerization proceeds in two stages. The first stage is characterized by high polymerization rate and slow initiation relative to propagation. During this stage molecular weight decreases or does not change and MWD increases with conversion. In the second stage considerably slower quasiliving polymerization of styrene occurs. The quasiliving nature of the styrene polymerization by the CumOH/AlCl₃ · OBu₂ system is proved and mechanistic scheme of the polymerization is proposed.     

Optimization of inoculum to substrate ratio for enhanced methane yield from leather fleshings in a batch study

One of the most significant issues of the last few decades has been tracing for renewable energy sources. Animal fleshing (ANFL) is the most common proteinaceous solid waste accured during the production of leather and it must be disposed of in an environmentally responsible manner. This paper is attempts to assess the biogas production from solid waste originating from the chrome based tannery. Anaerobic digestion of these wastes will be a viable option for waste stabilization and energy production in the form of biogas to be utilized in the industry. The bio-methane potential of the wastes were examined by mixing these wastes with various sources of inoculum and different inoculum to substrate (I/S) ratio considered. The batch experiments were carried out in 2.5 l glass reactors with a various source of inoculumviz., Cow Dung (CD), Elephant Dung (ED) and Bio-Digested Slurry (BDS) with varied inoculum to substrate (LFs) ratios for a retention time of 50 days with replications. The results obtained from the experiments showed that BDS:LF (25:75) had the highest gas production of 14505 ml (651.85 ml CH₄g^?1 VS) followed by CD:LF (50:50) produced 12072.5 ml (789.36 ml CH₄g^?1 VS) and ED:LF (75:25) produced 11252.5 ml (1492.08 ml CH₄g^?1 VS)with a methane content of 63.77, 61.92 and 62.72%, respectively.     

In situ sensing of the middle atmosphere with balloonborne near-infrared laser diodes

Since 1997, two near-infrared laser diode sensors have been developed with the support of the CNES, the French space agency, to provide in situ data of H(2)O, CH(4) and CO(2) in the middle atmosphere. The realized instruments were flown from stratospheric balloons within the framework of European campaigns for the study of stratospheric ozone and water vapor and were involved in the validation of the ODIN and ENVISAT satellites. In this paper, we describe the developed laser probing technique, we report atmospheric measurements and finally we discuss future perspectives, particularly the in situ laser sensing of the lower atmosphere of Mars and the implication of the laser hygrometers in balloon campaigns at mid-latitudes and tropical regions to investigate the sources and sinks of stratospheric H(2)O.     

27Al和29Si MAS-NMR对Mo/HZSM-5催化剂的研究

使用＾２９Ａｌ固体离分辨核磁技术对甲烷无氧芳构化催化剂Ｍｏ／ＨＺＳＭ－５分子筛进行了研究，发现ＨＺＳＭ－５分子筛本体中仅含有少量非骨架Ａｌ，Ｍｏ物种与分子筛骨架Ａｌ的相互作用随Ｍｏ担载量以及焙烧的温度的升高而增加，在高温焙烧下，Ｍｏ物种会使分子筛骨架严重脱铝，并且生成Ａｌ２（ＭｏＯ４）３新相，最终导致分子筛骨架塌陷，催化性能下降。     

Reaction of 4,4′-dimethyldiphenyl ether with phosphorus trichloride in the presence of anhydrous aluminum chloride

The reaction of 4,4-dimethyldiphenyl ether with phosphorus trichloride in the presence of anhydrous aluminum chloride was studied. This reaction affords 2,8-dimethyl-10H-10⁵-phenoxaphosphine 10-oxide as virtually the only product. In air, the latter in an alkaline solution is quantitatively transformed into 10-hydroxy-2,8-dimethyl-10H-10⁵-phenoxaphosphine 10-oxide.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2762–2765, December, 2004.     

Mo、W金属氧化物对CH4/CO2重整Ni基催化剂性能的影响

用XRD、XPS、元素分析、TEM和活性评价等方法研究过渡金属氧化物MoO3和WO3对SiO2负载的Ni基催化剂物理化学性质和CH4/CO2重整制合成气催化性能的影响.结果表明,在负载型的镍催化剂中,MoO3和WO3的添加一方面提高了Ni的核外电子密度,减弱了对CH4深度裂解积炭;另一方面使催化剂表面镍的相对浓度降低,结构上起到了隔离、分散金属颗粒的作用,氧的相对浓度升高,有效提高了催化剂的抗烧结和抗积炭能力,显示出较好的催化稳定性.     

用高效液相色谱法优化苯与对氯氯苄烷基化反应催化剂

用高效液相色谱法优化苯与对氯氯苄烷基化反应催化剂刘红霞张书胜袁倬斌＊（郑州大学分析测试中心郑州）（中国科学技术大学研究生院北京１０００３９）关键词氯－二苯甲烷，制备，三氯化铝，硝基苯，硝基乙烷，高效液相色谱法１９９７－０３－３１收稿，１９９７－０９－...     

对甲烷氧化偶联W－Mn／SiO＿2催化剂Na＿2WO＿4的流失及其影响的考察

用ＸＲＤ、ＦＴ－ＩＲ、ＥＳＲ、Ｈ２－ＴＰＲ和ＴＰＯ等方法，对Ｎａ２ＷＯ４－Ｍｎ２Ｏ３／ＳｉＯ２催化剂和其经水煮处理的一系列样品进行了表征．实验发现该催化剂中的结晶态Ｎａ２ＷＯ４易于流失，单层分布的Ｎａ２ＷＯ４在苛刻的处理条件下也有可能流失．依此，探讨了上述流失现象与Ｎａ２ＷＯ４－Ｍｎ２Ｏ３／ＳｉＯ２催化剂的催化活性及该催化剂在长时间反应中发生的ＳｉＯ２相变之间的关系，证明了结晶态Ｎａ２ＷＯ４的流失对该催化剂甲烷氧化偶联反应的催化活性只有轻微的影响，单层分布Ｎａ２ＷＯ４的流失可造成催化剂中Ｍｎ从Ｍｎ３＋转变为Ｍｎ２＋，并使催化剂的催化活性明显降低．但在水煮条件下，无论是结晶态的还是单层分布，Ｎａ２ＷＯ４的流失都没有对ＳｉＯ２的α－方石英结构产生影响     

负载型镍金属催化剂上甲烷与二氧化碳重整制合成气

报道了负载型Ｎｉ金属催化剂的表面特征和对ＣＨ４与ＣＯ２重整制合成气的催化性能，反应结果和ＴＰＲ，ＸＲＣ结果表明：Ｎｉ担载量为９．０％的催化剂具有最佳的反应性能，Ｎｉ组分以高散表面化合物形式存在，助剂对催化剂活性的影响随载体和添加方式的不同较大差异，其中少量ＭｇＯ，Ｌａ２Ｏ３对改善催化剂的稳定性和抗积碳能力有十分显著的效果，载体和制备方法对催化剂性能具有明显影响，其中浸渍法制备的Ｎｉ／ＭｇＯ催化剂不