铅电极上电聚合聚苯胺及其析氧电催化性能研究

在苯胺-硫酸电解液中,采用电化学阳极氧化法在纯铅表面电沉积制备聚苯胺(PAn)膜层。探讨了苯胺电聚合过程的影响因素及其规律,并考察了所得Pb/PAn膜电极材料的析氧电催化特性。结果表明,在一定的恒电流密度下,聚苯胺的沉积量与时间成正比;与空白Pb电极相比,Pb/PAn膜电极的析氧电位负移0.13~0.36V,交换电流密度提高2~4个数量级,显示出良好的析氧电催化特性。作为析氧阳极,Pb/PAn膜电极在有色金属电解提取等方面具有潜在应用价值。     

钛基涂层氧化物析氧阳极材料的研究进展

介绍了钛基涂层氧化物析氧阳极(DSA)的制备方法,包括热分解、磁控溅射、溶胶–凝胶和电沉积等方法。分析了DSA阳极的析氧原理。指出了DSA电极存在的问题及未来的发展趋势。     

电沉积制备多孔Ni-Fe-Sn合金电极及其析氧性能

采用直流电沉积法在铜箔表面合成了多孔结构的Ni–Fe–Sn合金,用扫描电子显微镜、X射线能谱仪和X射线衍射仪对合金的微观组织形貌和相态进行了表征,用电化学工作站测试了合金电极在碱性环境中的析氧性能。结果表明,Ni–Fe–Sn合金电极主要由Ni3Sn2和FeNi3相组成,电极表面形成了多孔结构。在30wt% KOH溶液中,Ni–Fe–Sn合金的析氧过电位仅为261 mV(电流密度10 mA/cm2),Tafel斜率为69.9 mV/dec。电极在10 mA/cm2电流密度下能稳定工作12 h以上,具有良好的电化学稳定性。     

碳纸负载铅电极的制备及其催化顺丁烯二酸电还原合成丁二酸

通过一步电沉积法制备CP@Pb电极,并将其用于催化顺丁烯二酸（C₄H₄O₄）电还原反应合成丁二酸（C₄H₆O₄）。利用SEM、TEM、XRD等手段对CP@Pb电极表面结构、物相组成等进行表征,通过CV及CP等方法研究CP@Pb电极在酸性环境中对C₄H₄O₄的电还原催化行为。结果表明,CP@Pb电极对C₄H₄O₄电还原具有良好的催化性能;反应温度为318.15 K时,在0.25 mol/L H₂SO₄+0.30 mol/L C₄H₄O₄中还原电流密度达到191.3 mA/cm²（-1 V）;当还原电流密度为120 mA/cm²时,合成丁二酸的纯度为96%。     

电沉积法制备碱性电解水镍基析氧电极的研究进展

在“碳达峰、碳中和”的目标下,绿氢成为极具前景的清洁能源。碱性电解水制取绿氢技术商业化程度最高,但由于析氧反应(OER)动力学过程缓慢且需要较高的过电位,成为制约电解水电极效率的主要瓶颈。商业电解槽中广泛使用的镍网或泡沫镍电极的OER性能仍有很大提升空间,在其上复合镍基催化功能层,开发新型高活性的析氧电极有利于提高电极效率,降低制氢成本。电沉积技术具有工艺简单、条件温和、利于放大生产自支撑电极的优势,成为工业化生产OER电极的理想工艺之一。本文综述了近年来利用电沉积技术制备的镍基析氧电极并用于碱性电解水的研究进展。采用电沉积技术在镍网或泡沫镍基底上制备镍(氢)氧化物、双金属及多元金属以及非金属掺杂的镍基催化剂作为催化功能层,通过增强催化功能层的电导率及金属间的协同作用、增加活性位点数量、减小扩散路径以及改变表面原子构型等方式提高镍基自支撑电极的OER性能。最后,展望了镍基自支撑电极在电解水领域的应用,同时指出了电沉积法制备电极材料存在的挑战。     

不锈钢基ZnO/PbO2阵列电极的制备及其析氧电催化性能

以不锈钢(SS)为基体,聚苯乙烯(PS)微球为模板,采用直流电沉积法制备了SS/ZnO/PbO2阵列电极.通过扫描电镜(SEM)分析和线性扫描伏安法(LSV)测试,研究了电流密度、施镀时间和Pb(NO3)2质量浓度对电极活性层微观形貌和析氧电催化性能的影响.结果表明,在电流密度5.0 mA/cm2和Pb(NO3)2质量浓度190 g/L的条件下施镀25 min所得SS/ZnO/PbO2阵列电极表面呈规则的花瓣状阵列结构,晶粒均匀、致密,电催化活性优异.     

电沉积Ni-S-Co/ZrO2复合电极及其催化析氢性能

在镀液中悬浮粒径约为200~400 nm 的ZrO2固体颗粒,以电沉积方法制备了Ni-S-Co/ZrO2复合电极。XRD和SEM测试结果表明,沉积层由非晶态的Ni、Co、S和单斜晶型的ZrO2粒子组成。镀层表面呈团粒状结构,无裂隙,与基体结合牢固。电化学测试结果表明,25 ℃时,Ni-S-Co/ZrO2复合电极在28％NaOH溶液中,在电流密度100 mA•cm-2下的超电势为145 mV,与未复合纳米ZrO2粒子的Ni-S-Co电极相比降低了50 mV。表明超细ZrO2的掺入有效提高了电极对析氢反应的催化效果。实验表明,沉积的最佳电流密度为70 mA•cm-2,最适宜的ZrO2用量为15 g/L,采用Ni-S-Co作为过渡层可以显著改善复合镀层与基体的结合。     

电沉积镍铁锰三元纳米片在析氧反应中的性能研究

电解水制氢技术作为当下最有效的制氢技术之一,低成本、高性能的电催化剂是提高电解水效率的理想选择。本文采用了一步电沉积法在泡沫镍上制备镍、铁、锰三元纳米片(NiFeMn)作为析氧反应(OER)电催化剂。当电流密度为20mA·cm^-2时,过电位达到297mV,Tafel斜率达到了143.2mV·dec^-1,经过了12小时的I-T测试后,其电流密度为86mV·cm^-2,表明该材料具有较好的稳定性和活性。NiFeMn纳米片良好的OER性能可能是由于其高的电化学活性表面积,为OER反应提供了更多的活性位点。     

电解合成丁二酸的研究进展

综述了国内外电解合成丁二酸的方法,详细介绍了电解反应过程中阴极材料、阳极材料、电解槽结构和隔膜材料的发展趋势.分析结果表明铅及铅合金阴极凭借其自身的优势,仍然是工业生产所采用的最主要的阴极材料;最适合的阳极材料是钛基氧化钌、铱或钽铱钛合金;而且无需使用任何形式的隔膜;未来最具有应用前景的研究方向是Ti或Ti/TiO2阴极.     

荧光环氧琥珀酸共聚物的合成及性能研究

以2-氨基噻唑和自制的环氧琥珀酸盐（ESA）为原料合成了含荧光标记的环氧琥珀酸共聚物,研究了产物的荧光性能和阻垢、缓蚀性能。实验表明,该荧光标记聚合物的荧光强度与其浓度呈一定的线性关系;在浓度为20 mg/L的条件下,该聚合物的阻垢率达到85%,缓蚀率为56.18%。     

无隔膜电化学合成丁二酸清洁工艺研究

通过对合成丁二酸新电化学体系的研究,设计了无隔膜电解装置,开发出了低能耗、高收率、无污染的丁二酸电化学合成高效清洁工艺.产品总收率可达98.5％,吨产品直流耗电量小于1 500 kW·h,母液可循环利用.     

SnO2-Sb2O3-CeO2/Ti电催化电极制备及氧化苯酚研究

采用电沉积制备中间层,热分解制备表层的方法制备了钛基铈掺杂锡锑涂层电极,利用SEM、EMPA、动电位扫描,研究了电极涂层形貌、元素组成分布、选择催化性.结果表明:电极表面涂层颗粒分布均匀,电极涂层有较大的表面积,Sn、Sb、Ce 3种元素分布较均匀;电极有较高的析氧电位.苯酚降解试验表明:低浓度时苯酚和CODCr有较高...     

Clarification of succinic acid fermentation broth by ultrafiltration in succinic acid bio–refinery

BACKGROUND: Succinic acid is an important precursor chemical for the synthesis of high value‐added products. In this work, ultrafiltration was first investigated to clarify succinic acid fermentation broth by integrating fermentation and separation and removal processes of the product in situ. Four different ultrafiltration membranes (PES 100 kDa, PES 30 kDa, PES 10 kDa and RC 10 kDa) were used in this work. RESULTS: Results indicate that ultrafiltration is feasible for clarifying succinic acid fermentation broth. Almost all the microorganism cells (99.6%) were removed from the fermentation broth. Proteins were also removed effectively by all the membranes studied. The removal rate was 79.86% for PES 100 kDa, 86.43% for PES 30 kDa, 86.83% for PES 10 kDa, and 80.06% for the RC 10 kDa. After ultrafiltration, a clearer permeate was obtained compared with that from centrifugation. CONCLUSION: Membranes operating at high flux are always susceptible to rapid fouling. Compared with molecular weight cut‐offs (MWCO), membrane material has a significant influence on the flux. Membrane flux measured in this study shows industrial potential of this technology in treatment of succinic acid fermentation broth. © 2012 Society of Chemical Industry     

产琥珀酸放线杆菌固定CO_2制备丁二酸

在富含CO2的厌氧环境下,产琥珀酸放线杆菌NJ113固定CO2合成丁二酸作为主要代谢终产物。在5 L发酵罐探讨了培养条件对产琥珀酸放线杆菌NJ113固定CO2制备丁二酸的影响。考察了CO2供体形式、通气量、搅拌转速、培养温度和pH值对产琥珀酸放线杆菌NJ113厌氧发酵过程中CO2固定速率以及丁二酸产率的影响。结果表明,选择CO2气体作为CO2供体,CO2通气量为0.75 L/min,搅拌转速达到200 r/min,培养温度为37℃,NaOH调节pH值为6.6,可增加细胞内可利用的CO2。在此优化条件下培养,CO2固定速率达到0.6 g/(L.h),丁二酸产率达到1.61 g/(L.h)。     

Electrolytic synthesis of succinic acid in a flow reactor with solid polymer electrolyte membrane

This paper describes the galvanostatic synthesis of succinic acid from maleic acid in an ion exchange membrane flow cell. The electrolysis was carried out at stainless steel, lead and copper cathodes under variable conditions of current density and substrate concentration. Depending upon the experimental conditions, the yield of succinic acid varied from 95 and 99% with a coulombic efficiency of 80–99%. The product was characterized by various physicochemical techniques, viz. ¹H-NMR, IR and UV–Visible spectroscopy and elemental analysis. The operational conditions giving maximum yield of product were identified. The mechanism of electrochemical reduction of maleic acid and advantages of using a catholyte without supporting electrolyte are discussed.     

Surface activation of manganese oxide electrode for oxygen evolution from seawater

Utilizing the fact that the equilibrium potential of oxygen evolution is lower than that of chlorine evolution, oxygen evolution in seawater electrolysis was enhanced by decreasing the polarization potential under galvanostatic conditions through increasing the effective surface area of manganese oxide electrodes. Electrodes were prepared by a thermal decomposition method. IrO2-coated titanium (IrO2/Ti electrode) was used as the substrate on which manganese oxide was coated (MnOX/IrO2/Ti electrode). Subsequently, oxide mixtures of manganese and zinc were coated (MnOX–ZnO/MnOX/IrO2/Ti electrode). The effective surface area of the MnOX–ZnO/MnOX/IrO2/Ti electrodes was increased by selective dissolution of zinc (leaching) into hot 6M KOH. The oxygen evolution efficiency of the MnOX/IrO2/Ti electrode was 68–70%. Leaching of zinc from the MnOX–ZnO/MnOX/IrO2/Ti electrodes with 25mol% or less zinc led to a significant increase in the oxygen evolution efficiency. The maximum efficiency attained was 86% after leaching of zinc from the MnOX–25mol%ZnO/MnOX/IrO2/Ti electrode. However, large amounts of zinc addition, such as 40mol% or more are detrimental because of a decrease in the oxygen evolution efficiency. This is due to the formation of a double oxide, ZnMnO3, which is hardly dissolved in hot 6M KOH.