钛基Ru-La-Ti涂层阳极的电催化性能

利用热分解法制备了不同La含量的钛基Ru-La-Ti涂层阳极，并研究了所制备涂层的电催化性能。结果表明，在Ru-Ti涂层阳极中掺杂稀土元素La可以提高涂层阳极的电催化活性，且La的掺杂量存在一个最佳范围(La的摩尔分数O．2)。涂层阳极电催化活性提高的原因在于La的引入可以提高涂层的有效活性表面积。     

Application of electrode materials and catalysts in electrocatalytic treatment of dye wastewater

The dye industry produces a large amount of hazardous wastewater every day worldwide, which brings potential threaten to the global environment. As an excellent method for removal of water chroma and chemical oxygen demand, electrocatalytic methods are currently widely used in the treatment of dye wastewater. The selection and preparation of electrode materials and electrocatalysts play an important role on the electrocatalytic treatment. The aim of this paper is to introduce the most excellent high-efficiency electrode materials and electrocatalysts in the field of dye wastewater treatment. Many electrode materials such as metal electrode materials, boron-doped diamond anode materials and three-dimensional electrode are introduced in detail. Besides, the mechanism of electrocatalytic oxidation is summarized. The composite treatment of active electrode and electrocatalyst are extensively examined. Finally, the progress of photo-assisted electrocatalytic methods of dye wastewater and the catalysts are described.     

掺杂铁的二氧化铅电极的制备及性能研究

主要研究了不锈钢/PbO₂电极和掺杂的不锈钢/Fe-PbO₂电极的制备,用其对有机废水的处理效果及影响因素来评价该电极的性能。实验结果表明:采用恒流阳极电沉积技术制备的PbO₂电极,掺杂和不掺杂铁的电极主要成分都是β-PbO₂;两电极外观都没有明显的裂纹等缺陷,掺杂铁的二氧化铅镀层颗粒大小镶嵌,很好地清除了内应力,保证了基材与镀层不易脱落,未掺杂铁的二氧化铅镀层颗粒细小、均匀,内应力有些大;将Fe（NO₃）₂添加至电沉积溶液中,致使PbO₂电沉积层的析氧电位向正方向移动,改善了PbO₂电极的电催化活性,以至于更有利于氧化降解有机物。用改性的Fe-PbO₂电极和常规的PbO₂电极分别降解初始浓度相同的邻苯二酚和苯酚有机物废水,改性的Fe-PbO₂电极对苯酚和邻苯二酚的去除率均高于常规的PbO₂电极。掺杂铁的二氧化铅电极较未掺杂电极有更好的电催化活性,更高的析氧电位,更适宜于用作电催化阳极。     

Electrosynthesis of 2,3-dimethyltartaric acid from pyruvic acid in acid medium

This study reports the electrohydrodimerization of pyruvic acid to 2,3-dimethyltartaric acid in sulphuric acid medium (0.5 M H₂SO₄) on a lead cathode. The main products detected were lactic acid and 2,3-dimethyltartaric acid. The selectivity towards the formation of 2,3-dimethyltartaric acid was studied vs. pyruvic acid concentration in sulphuric acid solution, at −1.1 V vs. MSE. The best selectivity of 2,3-dimethyltartaric acid reached 69% for an initial concentration of 1.7 M pyruvic acid. The yield of pyruvic acid was 84%.     

Performance of Methanol Oxidation Catalysts with Varying Pt:Ru Ratio as a Function of Temperature

This paper describes the effects of varying the Pt to Ru ratio in carbon-supported catalysts for methanol oxidation as a function of temperature. Previously these effects were studied in isolation, but now it is shown that the composition of a given catalyst as a function of temperature is extremely important for its activity towards methanol oxidation. Platinum rich 3:2 atomic ratio catalysts perform better than a 1:1 catalyst at 25 °C, where only Pt is believed to be active towards methanol dehydrogenation, since this process is a highly thermally activated process on Ru sites. This result is reversed at 65 °C, where the 1:1 catalyst displays much higher currents across the entire range of polarization. This may result from methanol dehydrogenation occurring on both Ru and Pt sites at higher temperatures. At an intermediate temperature, 45 °C, the 3:2 catalyst is seen to perform better at lower current values, while the 1:1 catalyst is superior at higher current densities, with the crossover occurring at 62 A g^–1. As a consequence, when designing fuel cell catalysts, the composition of the catalyst employed should be tailored with respect to the exact operating conditions, in order to promote optimum fuel cell performance.     

精制棉电催化氧化技术及工艺研究

利用电催化氧化技术使棉短绒发生快速断裂反应,同时使木质素、果胶等带色基团退色,减少污水处理难度。生产的精制棉纤维素一致性率、a-纤维素含量达到98%以上,聚合度降低到700DP,反应时间由原来的2.5h缩短到20min,色度减少80%。通过实践,实现了生产精制棉节能降耗的目的,且明显减轻了对环境的污染。     

Investigation on the electrocatalytic characteristics of SnO_2 electrodes with nanocoating prepared by electrodeposition method

SnO2 electrodes have many advantages in the degradation of toxic or bio-refractory organic wastewater,and SnO2 is a kind of anode material which has the potential to be widely used.Electrocatalytic effi-ciency and service life of Ti\SnO2 electrodes are key factors that can influence its applications.In order to enhance the electrocatalytic characteristics of Ti\SnO2 electrodes,a type of electrocatalytic electrode with nanocoating was prepared by direct current(DC)electrodeposition method and thermal oxidati...     

聚硫堇/纳米金修饰电极对NO2-的电催化氧化及分析应用

研究了一种基于聚硫堇/纳米金复合材料修饰电极对NO2-的电催化氧化。相对于裸玻碳电极,聚硫堇-纳米金协同催化效应使NO2-的氧化电流增强,过电位降低。详细讨论了聚合膜的厚度、纳米金吸附时间、pH缓冲介质、pH值以及干扰离子对NO2-氧化电流的影响。在最优实验条件下,测得NO2-的线性范围为3.0×10^-6～1.0×10^-3 mol/L,检测限为1.0×10^-6 mol/L。该修饰电极具有灵敏度高、稳定性和重现性好、抗干扰能力强的特点,可用于实际样品中NO2-含量的测定,结果满意。     

氨络合物体系中Ti基IrO2涂层阳极的析氮过程

采用线性扫描技术研究了氯盐氨络合物体系中Ti基IrO2涂层阳极的析氮过程,对3种含有不同氧化物涂层电极的析氮电催化性能进行了比较,并结合扫描电镜(SEM)及能谱(EDX)探讨了不同析氮电催化活性的原因.研究结果表明:当电极电位低于1.1 V(vs SCE)时,Ti基IrO2涂层阳极析气反应主要为析氮反应,氮气的产生主要是由于氨水在电极上发生电化学氧化引起的;Ti基含PdRuTi的IrO2涂层阳极具有最佳的析氮电催化活性,其可能原因是金属元素PdRuTi的存在导致该电极表面特征裂纹最宽且最深,氧化物涂层总析氮面积增多,电催化活性增加.     

负载型TiO2纳米薄膜电极光电催化氧化甲醇的研究

介绍了负载不同晶型TiO2薄膜电极的制备，并研究了聚乙二醇加入量、活化条件等对不同晶型、不同形貌、不同粒径纳米TiO2薄膜电极的光电催化活性的影响。结果表明：聚乙二醇加入量有一最佳值；且纳米级锐钛矿型TiO2和金红石型TiO2分别经600℃和400℃煅烧后，光电催化性能最好；粒径越小催化活性越高．当粒径小于25nm时，可显示出量子尺寸效应。