Pt-WC/Mnt三元纳米复合材料的制备及其电催化性能

以剥离后的蒙脱石(Mnt)片层为载体、六氯化钨(WCl6)为钨源,通过浸渍负载及原位还原碳化获得了碳化钨(WC)与蒙脱石(Mnt)纳米复合材料,然后将氯铂酸(H2PtCl6)通过浸渍负载于复合材料上,并在氢气(H2)中还原得到Pt-WC/Mnt三元纳米复合催化材料。采用X射线粉末衍射和透射电子显微镜对三元纳米复合催化材料的物相、形貌和结构进行表征,采用三电极体系和循环伏安法测试了样品的电催化性能。结果表明:样品物相主要为WO3和WC,蒙脱石片层结构明显,铂(Pt)纳米粒子均匀分布于WC/Mnt复合材料的外表面。Pt-WC/Mnt三元纳米复合材料对甲醇电催化氧化具有较高的催化活性,并且在酸碱体系中均具有良好的稳定性。     

乙二醇高温还原制备燃料电池核壳结构Cu@Pt-Pd电极的研究

通过对以碳为核心的燃料电池电催化剂Cu@Pt-Pd的制备方法的研究,以还原法成功将Cu、Pt、Pd还原到了靶核C上制备出了核壳结构电催化剂Cu@Pt-Pd。该催化剂以Cu为核来提升催化剂的表面积比,同时掺杂金属Pd,降低贵金属铂的使用量,在提高催化效率的同时可以降低成本。经过对所制备的催化剂的XRD和CV的测试与分析,探究出制备的成品具有一定的提升氧化还原反应的催化效率的能力,同时该制备方法简单易于操作,利于大量制备。     

Oxygen reduction reaction and hydrogen evolution reaction catalyzed by carbon-supported molybdenum-coated palladium nanocubes

Oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) are two important processes for electrochemical energy storage and conversion. Herein, we describe the preparation of carbon-supported Pd nanocubes@Mo core@shell nanostructures as efficient dual catalysts for both ORR and HER. The core@shell structure was manifested by high-resolution transmission electron microscopy measurements, including high angle-angular dark field-scanning transmission electron microscopy and elemental mapping analysis. Further structural insights were obtained in X-ray diffraction and X-ray photoelectron spectroscopy measurements. The nanostructures exhibited apparent electrocatalytic activity toward both ORR and HER, and the performances were markedly higher than those without the deposition of a Mo overlayer. In ORR, the activity was even better than that of commercial Pt/C within the context of onset potential, specific and mass activities; whereas in HER, the performance of Pd nanocubes@Mo core@shell nanostructures remained subpar as compared to that of Pt/C in terms of the overpotential to reach the current density of 10 mA cm^?2, the Tafel slope was comparable and the stability was excellent. The excellent electrocatalytic performance can be attributed to the Pd-Mo synergistic effects imparted from the core-shell structure.     

金属酞菁/卟啉分子电催化CO2还原的研究进展

大气中日益增加的CO₂浓度导致了气候变化等环境问题。将CO₂催化转化为有价值的化学品具有重要意义。利用太阳能、风能等可再生能源产生的电能,通过电化学方法将CO₂还原转化为有价值的碳基化合物是最具有应用前景的方式。分子催化剂具有明确的结构和清晰的活性位点,可实现基于机理的性能优化。综述了近年来金属酞菁/卟啉分子在电催化CO₂还原为CO的实验和理论方面的最新研究进展。首先,介绍了金属酞菁/卟啉分子电催化CO₂还原为CO的详细机理。然后,重点介绍了如何通过分子分散和配体修饰提升金属酞菁/卟啉分子电催化CO₂还原为CO的活性和选择性。最后,讨论了金属酞菁/卟啉分子电催化CO₂还原存在的挑战及其可能的解决方案。     

新型包覆碳化钨载体负载Pd催化剂的性能

以Vulcan XC-72R活性碳作为碳源,采用高温热处理还原法,在活性碳表面原位还原钨酸铵,形成表面包覆钨的碳化物结构的载体。通过BET等当钨酸铵用量适宜时,形成的钨的碳化物的平均孔径较大,较大介孔所占比例较大,以其为载体制备的Pd催化剂Pd/WC-2其电荷传递阻抗和扩散阻抗都较小。催化剂Pd/WC-2对甲酸的氧化不但具有较高的活性,同时也具有很好的稳定性。     

Electrodeposited Pt nanorods on a novel flowered-like nanostructured NiCo alloy as an electrocatalyst for methanol oxidation

For the first time, a novel system of Pt nanorods supported on nano flowered-like structure NiCo alloy has been successfully electro-synthesized onto a glassy carbon electrode for the electrocatalytic oxidation of methanol. The electrodeposited system has been characterized using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The electrocatalytic efficiency of the electro-fabricated system of Pt/NiCo/GCE have been confirmed by cyclic voltammetric (CV) and current-time methods. It is discovered that the electrodeposited nano flowered NiCo alloy substrate has a great effect on the electrocatalytic properties of the electrodeposited Pt nanorods. The electrocatalytic efficiency of the new system for methanol oxidation reaction (MOR) is found to be 174 A/g_Pt. The effect of electrodeposition time for NiCo alloy has been studied. Also, the effect of pH, temperature, and concentration for the electrodeposition of Pt catalyst on the electrocatalytic properties of the Pt/NiCo/GCE have been studied for detection the optimum conditions. The mechanism of the electrocatalytic oxidation of methanol has been discussed. Furthermore, the stability and the corrosion resistance test of the Pt/NiCo/GCE system have been investigated by electrochemical impedance spectroscopy (EIS), Tafel plot and current-time methods.     

膜技术处理印染废水研究进展

介绍了膜分离及集成技术在印染水处理中的应用,分析了膜污染存在的原因及解决膜污染问题的研究现状,重点介绍具有自清洁功能的电催化膜及其抗污染机理.最新结果显示,电催化膜利用膜分离与间接氧化协同作用能够实现印染废水高效降解,是一种绿色环保的污水处理新技术,具有广阔的应用前景.开发具有抗污染、长寿命、高通量的膜材料以及集成技术...     

碳纳米管担载纳米银及其电催化甲醇氧化的研究

以水溶性离聚物聚（苯乙烯磺酸钠-co-丙烯酸）（PSA）接枝多壁碳纳米管为模板,制备了碳纳米管担载纳米银（AgNP@MWNT）,研究了在碱性条件下对甲醇氧化的电催化作用。结果表明接枝在MWNT表面的离聚物PSA有效地控制了AgNP在MWNT表面以2～4nm的尺寸均匀担载,促进了AgNP与MWNT之间的界面相互作用。制备的Ag@MWNT在水中能够稳定地均匀分散,在碱性条件下可有效地电催化甲醇氧化,抗甲醇中毒性能良好。     

电镀废水有机污染物的电催化氧化中试研究

采用新型钛基网状电极对电镀废水进行了电催化氧化研究,在间歇试验条件下考察了电流密度、处理时间和原水初始pH对有机污染物处理效果的影响,在连续试验条件下考察了工艺的稳定性,并结合GC-MS中间产物分析探讨了电催化氧化对废水可生化性的影响。结果表明,处理时间、电流密度和原水起始pH对COD去除效果有显著影响,优化的试验参数为:电流密度100 A.m-2,处理时间3 h,起始pH为中性。在该条件下,废水COD可由439 mg.L-1降至70 mg.L-1,且装置运行稳定,吨水处理能耗为5.7 kWh。长链烷烃等大分子有机物在电催化氧化过程中被分解为短链烷烃和小分子有机物,废水可生化性得到显著改善。     

载铂二氧化钛纳米管电极的制备及电催化性能

用水热法在二氧化钛纳米管上负载纳米铂微粒,制备出大比表面积、高表面原子数的载铂二氧化钛纳米管电极。 SEM和XRD分析证明纳米管上已负载20~30 nm的铂微粒。循环伏安测试结果表明：不含染料的体系中,载铂二氧化钛纳米管电极在0.13 V处的氧化峰电流密度为Pt片电极的10倍;含染料的体系中,载铂二氧化钛纳米管电极上对酸性大红GR的氧化峰电流密度达到Pt片电极上的4.2倍。对酸性大红GR的降解实验表明,载铂二氧化钛纳米管电极催化活性高、降解快速高效