Cu(Ⅱ)对显色体系DAmEM-V(Ⅴ)-H_3PO_4-Mn(Ⅱ)-Tween20阻抑作用的研究

在酸性介质中Cu(Ⅱ )能阻抑试剂DAmEM与V(Ⅴ )的显色反应。本文研究了该反应的动力学参数。反应的表观速率常数Ka=8.867× 1 0 - 2 /min ,表观活化能Ea=37.795kJ/mol。基于这种阻抑作用建立了一种测定Cu(Ⅱ )的动力学分光光度法 ,Cu(Ⅱ )在 1 .0 0～ 8.0 0 μg/2 5mL内准确检出。     

正交设计试验研究二安替比林对乙氧基苯基甲烷与钒(Ⅴ)的超高灵敏显色反应

以正交试验设计法研究了二安替比林对乙氧基苯基甲烷 (DAp EM)试剂与微量钒 ( )的超高灵敏显色反应 ,建立了测定钒 ( )的新体系。该体系的灵敏度为 ε=8.30× 10 6 L· mol- 1· cm- 1 ,线性范围为 2 .0 0～ 10 .0μg· L- 1 ,对测定 0 .2 0 μg· (2 5 m L) - 1 V( ) ,抗主要离子干扰量为 :Fe3+ ,Cu2 + (10 μg) ;Ce( ) (5 μg) ;F- (0 .5μg)。与单因素轮换法建立的体系相比 ,灵敏度和选择性有了很大的改善。该方法测定中草药样品中微量钒 ( )含量 ,结果满意     

正交设计试验研究二安替比林对乙氧基苯基甲烷与钒(V)的超高灵敏显色反应

以正交试验设计法研究了二安替比林对乙氧基苯基甲烷(DApEM)试剂与微量钒(Ⅴ)的超高灵敏显色反应,建立了测定钒(Ⅴ)的新体系.该体系的灵敏度为ε=8.30×106L@mol-1@cm-1,线性范围为2.00～10.0μg@L-1,对测定0.20μg@(25 mL)-1V(Ⅴ),抗主要离子干扰量为Fe3+,Cu2+(10μg);Ce(Ⅳ)(5μg);F-(0.5μg).与单因素轮换法建立的体系相比,灵敏度和选择性有了很大的改善.该方法测定中草药样品中微量钒(Ⅴ)含量,结果满意.     

在Mn(Ⅱ)存在下二安替比林苯基甲烷的合成及Pd(Ⅱ)的光度法研究

合成了二安替比林苯基甲烷(DAPM),并研究在Mn(Ⅱ)存在的沸水浴条件下,二安替比林苯基甲烷分光光度法测定微量钯的最佳显色条件。研究结果表明,本体系最大吸收波长λmax=480nm,表观摩尔吸光系数ε=1.08×105 L·mol~(-1)·cm~(-1);在50m L溶液中,钯(Ⅱ)的质量浓度在0~0.3μg/m L范围内符合朗伯-比尔定律。该体系选择性好,稳定时间长。运用于样品中微量钯的测定,结果满意。     

在Mn(Ⅱ)下二安替比林对甲氧基苯基甲烷与Cr(Ⅵ)的光度法研究

在Mn(Ⅱ)和1%(体积比)Tween-20条件下,研究了二安替比林对甲氧基苯基甲烷(DAPMM)与Cr(Ⅵ的显色反应条件,研究结果表明,最大吸收波长λ_(max)=450 nm,表观摩尔吸光系数ε=6.18×10~4L·mol~(-1)·cm~(-1);在50m L溶液中Cr(Ⅵ)的浓度在0~0.7μg/m L范围内符合朗伯-比尔定律。该体系对Cr(Ⅵ)选择性好,稳定性好,可用于微量及痕量Cr(Ⅵ)的样品测定,结果满意。     

二安替比—（邻—乙氧基）—苯基甲烷光度法测微量Cr（Ⅵ）

合成了新试剂二安替比林－（邻－乙氧基）－苯基甲烷（ＤＡｏＥＭ）；研究了在Ｍｎ（Ⅱ）存在下，ＤＡｏＥＭ与Ｃｒ（Ⅵ）生成橙黄色化合物。该化合物最大吸收位于４８０ｎｍ，表观摩尔吸收系数ε＝２．０８×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，化合物至少可以稳定８ｈ，服从比尔定律范围为４～２００μｇ／Ｌ，用于含铬废水和电镀废液中铬的测定，结果满意。     

二安替比林对溴苯基甲烷与Mn（Ⅳ）的显色反应的研究

在碱性介质中,加热时空气氧化ＭｎⅡ为ＭｎⅣ,在磷酸介质中,ＭｎⅣ与二安替比林对溴苯基甲烷生成橙色产物,最大吸收波长为４８０ｎｍ,摩尔吸光系数为２６７×１０４Ｌ·ｍｏｌ－１·ｃｍ－１,锰含量在０～４０μｇ／２５ｍｌ内符合比尔定律,用于测定茶叶中的ＭｎⅡ,操作简便、快速,结果满意。     

H3PO4中染料中性红对钢的缓蚀性能

用失重法研究了染料中性红对冷轧钢在1.0 mol/LH3PO4溶液中的缓蚀作用。结果表明：中性红对冷轧钢在1.0 mol/LH3PO4溶液中具有良好的缓蚀作用。缓蚀率先随缓蚀剂浓度的增加而增大,后减小,存在浓度极值现象;缓蚀率随温度的升高而增大。在吸附区间（25～150 mg/L）中性红在钢表面的吸附符合Temkin吸附等温式。通过热力学基本公式求出了相应的吸附热力学（吸附自由能△G0,吸附焓△H0,吸附熵△S0）;根据这些参数讨论了缓蚀作用机理。     

Catalytic combustion of SOFC stack flue gas over CuO and Mn2O3 supported by La0.8Sr0.2Mn0.67Cu0.33O3 perovskite

An efficient oxidation catalyst was developed to increase the combustion efficiency of unreacted CO, H₂, and CH₄ in flue gas of solid oxide fuel cell (SOFC) stack. Amorphous Cu‐Mn oxide catalyst (CuMnLa/Alumina) showed high catalytic activity, but significant degradation occurred due to phase transition to spinel structure at high temperatures (T > 650°C). La_0.8Sr_0.2Mn_0.67Cu_0.33O₃ perovskite (LSMC(p)) supported CuO or Mn₂O₃ exhibited improved thermal stability than CuMnLa/Alumina catalyst. Especially in case of 50Mn/LSMC(p), after the catalyst was exposed to 800°C for 24 h, T₅₀ of CO, H₂ and CH₄ was achieved at 170, 230, and 600°C, respectively. This result is much lower than that of CuMnLa/Alumina, which was exposed to the same condition. The high combustion efficiency is due to retention of the Cu²⁺‐Mn³⁺ redox couple, and supply of lattice oxygen from LSMC(p), especially at high temperature. © 2017 American Institute of Chemical Engineers AIChE J, 64: 940–949, 2018     

Effect of H3PO4 on the PbSO4/PbO2 electrode in H2SO4 solutions

The influence of H₃Po₄ small additions on the polarization behaviour of the PbSO₄/PbO₂ electrode, in H₂SO₄ solutions of different concentrations, was studied using the microelectrode technique and the coulometric method. The reference electrode was the Hg/Hg₂SO₄/H₂SO₄ electrode. The potentiogram analysis and the coulometric measurements show that the main effect of the H₃PO₄ is the drastic passivation of the electrode processes, within the potential range under study, ie the +800 mV to +1650 mV potential range. The Q_a and Q_c electricity amounts are of about 5–10 times smaller in the H₂SO₄ solution with H₃PO₄ addition, compared with the H₂SO₄ solution free of H₃PO₄ addition. A high increase of the oxygen evolution overvoltage could also be seen. Taking into account the ratio between the H₃PO₄ addition amount, in % (w/o) and the PbO₂ active mass per unit surface area, from the lead acid batteries, we can conclude that the small H₃PO₄ additions do not decrease the capacity of the active mass of the battery, but they hinder the insulator film formation between the active mass and the grid.     

一锅法负载磷酸法合成N-苯基马来酰亚胺

以顺丁烯二酸酐和苯胺为原料、二甲苯为溶剂,负载磷酸为催化剂,对苯二酚为阻聚剂,采用两步法合成了N-苯基马来酰亚胺,产品经核磁、红外表征,液相色谱分析,产品收率达到90%,纯度达到99.7%。最佳工艺条件为:n(苯胺)∶n(顺丁烯二酸酐)为1∶1.05,胺化反应温度为60～70℃,催化剂用量2.5g,环化反应温度为142℃,环化时间为2h。     

LiFe_(0.8)Mn_(0.2)PO_4的制备、表征及电化学性能研究

使用共沉淀法分别制备了纯相磷酸亚铁锂(LiFePO4)和磷酸亚铁锂掺锰材料LiFe0.8Mn0.2PO4,以期在不降低体积比容量的前提下提高磷酸亚铁锂材料的导电性。通过对产品的X射线衍射(XRD)分析,证实掺杂Mn2+并未改变磷酸亚铁锂的正交橄榄石型晶体结构;扫描电镜(SEM)显示LiFe0.8Mn0.2PO4比纯相磷酸亚铁锂具有更小的粒径,从而有利于Li+的扩散,进而有助于提高其电化学活性;通过对产品的电化学性能测试比较,掺杂Mn2+后的材料,无论是放电容量或是高倍率下的循环性能都优于纯相磷酸亚铁锂。     

Catalytic Epoxidation of Styrene by Molecular Oxygen over a Novel Catalyst of Copper Hydroxyphosphate Cu2(OH)PO4

Catalytic epoxidation of styrene by molecular oxygen over a novel copper hydroxyphosphate catalyst, Cu₂(OH)PO₄, was studied. Catalytic data show that the catalyst Cu₂(OH)PO₄ is very active, and the main products are benzaldehyde and styrene epoxide. Some important factors associated with the catalytic activity and selectivity have been investigated extensively.     

蓖麻油磷酸催化脱水研究

以H3PO4为催化剂,在减压下对蓖麻油催化脱水进行了研究。利用正交实验考察了反应温度、反应时间、催化剂用量、真空度对脱水反应的影响。得出的最佳工艺条件为:反应温度250℃、反应时间90min、催化剂用量1.0%、真空度600×133.3Pa。在该工艺条件下制得的脱水蓖麻油平均碘值达到138,且色泽较浅。     

蓖麻油磷酸催化脱水研究

以Hh3PO4为催化剂,在减压下对蓖麻油催化脱水进行了研究.利用正交实验考察了反应温度、反应时间、催化剂用量、真空度对脱水反应的影响.得出的最佳工艺条件为:反应温度250℃、反应时间90min、催化剂用量1.0%、真空度600mmHg.在该工艺条件下制得的脱水蓖麻油平均碘值达到138,且色泽较浅.     

Electrochemical behaviour of Mn3+/Mn2+, Co3+/Co2+ and Ce4+/Ce4+ redox mediators in methanesulfonic acid

The redox behaviour of Mn³⁺/Mn²⁺, Co³⁺/Co²⁺ and Ce⁴⁺/Ce³⁺ mediators commonly used in indirect oxidation of organic compounds were evaluated in methane sulfonic acid on a glassy carbon working electrode employing cyclic voltammetry. Manganic methanesulfonate exhibits higher instability in dilute methanesulfonic acid. The solid MnO₂ formed during disproportionation on the glassy carbon electrode further affects the reproducibility. Cobaltic methanesulfonate formation occurs only at oxygen evolution region rendering the overall oxidation process less efficient. Ceric methane sulfonate formation is highly efficient over a wide acid concentration range. Ceric methanesulfonate can also be employed over a wide temperature range to oxidize different aromatic compounds.     

磷酸活化废弃稻壳制备活性炭的研究

采用H3 PO4为活化剂、稻壳为原料,通过微波和马弗炉两种方法制备活性炭。详细考察了浸渍时间、料液比、活化剂浓度、微波功率或活化温度、以及活化时间的影响。结果显示,在磷酸浓度35％、料液质量比1：4、浸渍时间3 h的条件下,采用400 W微波功率辐射8 min,制备的活性炭亚甲基蓝吸附值达到232 mg/g,若采用马弗炉600℃焙烧10 min,活性炭的亚甲基蓝吸附值达到226 mg/g。