石墨碳黑负载Pt-PbOx的制备及氧还原催化性能研究

氧气还原反应(Oxygen Reduction Reaction)是绝大部分燃料电池的阴极反应,往往比阳极氧化反应需要更多的催化剂来推动.本文利用一锅水热法制备石墨碳黑负载铂(Pt/GCB)催化剂,采用旋转搅拌合成Pt-PbO_x纳米复合材料,通过电化学性能测试发现所制备的Pt-PbO_x/GCB复合材料具有优异的ORR催化活性和电化学稳定性.     

新型MgO限域NiCo合金碳基催化剂用于苯胺与脂肪醇的N-烷基化反应（英文）

寻找一种成本效益高且可扩展的策略来制备高效的合金催化剂,用于N-烷基化反应仍然是一个挑战。通过自模板化策略,采用Ni-Co-Mg三金属MOFs(命名为Ni-Co-Mg@H₂dhbdc)作为前驱体,一步热解合成了香蕉状形貌固溶体限域NiCo合金的碳基新型纳米催化剂(命名为NiCo/MgO-C)。将此催化剂应用于苯胺与脂肪醇的N-烷基化反应,由于其独特的结构(如NiCo纳米颗粒的小尺寸,电子密度的增强传输)和NiCo合金特性,表现出卓越的性能,与双金属MOFs衍生催化剂(如Ni/MgO-C和Co/MgO-C)相比更优越。在热解过程中,发现Ni-Co-Mg@H₂dhbdc前体能够提高NiO-MgO或CoO-MgO固溶体中NiO或CoO物种的还原程度。因此,这种Ni-Co-Mg@H₂dhbdc MOFs模板化的策略是一种简单且可控的方法,用于合成负载型固溶体纳米合金催化剂应用于多相催化反应。     

固相研磨法制备Co-N掺杂介孔碳氧还原催化剂实验

以SBA-15为硬模板, Salen-Co为单一前驱物,采用固相研磨法合成了Co-N共掺杂石墨化的有序介孔碳材料(Co-N-C)。结果表明,实验所得到的Co-N-C-800在碱性介质中显示出了卓越的ORR的电催化活性,并呈现出优于Pt/C催化剂的抗甲醇性和稳定性。最重要的是,固相研磨法为有序介孔氧还原催化剂的制备提供了一种简便、省时、价格低廉的方法。     

硫氮共掺杂的有序介孔碳用于氧还原反应的实验研究

硫氮共掺杂的有序介孔碳(SN-OMC)是通过一步复制路线合成的,双硫腙在SN-OMCs的制备过程中作为单一的碳、硫、氮前驱物。对此非金属催化剂进行物理化学表征,并在碱性电解质中对其催化氧还原反应(ORR)的电化学性进行了评估。在900℃下得到的SN-MOC展现了用于ORR反应的高电催化活性,以及可观的耐久性和耐甲醇性;介孔碳孔道中硫和氮的协同效应有利于提高SN-MOC的氧还原催化活性。     

聚钴卟啉的制备及其氧还原催化性能

金属卟啉具有高的共轭结构和化学稳定性,在酸性和碱性介质中均表现良好的ORR电催化活性。以周边不含有易聚合官能团的四苯基钴卟啉(Co TPP)为单体,采用循环伏安电化学聚合的方法制备四苯基钴卟啉聚合物(p Co TPP)薄膜。由于生成的聚合物具有更高的共轭结构,p Co TPP薄膜的紫外光谱图中Soret带和Q带均发生红移,且吸收峰变宽。结果表明,p Co TPP在碱性介质中对氧分子具有良好的电催化活性,为金属卟啉氧还原反应(ORR)催化剂的研究提供新的方向,有望成为燃料电池非贵金属氧还原催化剂材料。     

CoV基电催化剂合成及锌-空电池性能研究

贵金属催化剂通常被认为是氧还原反应和氧析出反应缓慢的四电子转移机理的最佳电催化剂.但由于其成本高,资源稀少且稳定性不足,使大规模的商业化受到了限制.因此,在同等催化性能的条件下,低成本且环境友好的非贵金属电催化剂将成为未来电催化剂工程的重点.以二氰二胺为碳源,利用基团配位作用结合冷冻干燥策略,经过碳化处理制备CoV碳纳米管复合材料(命名为CoV-NC).通过扫描电镜、X-射线衍射光谱、N2吸附—脱附曲线等对样品进行形貌和结构表征.在0.1 M KOH电解液中,CoV-NC催化剂的ORR起始电位为0.931V,并具有较高的极限电流密度.在电流密度为10 mA·cm-2时,OER电压仅为1.63 V,证明CoV-NC具有较好的ORR和OER催化活性.作为空气—正极材料组装成的一次锌-空电池,在5 mA·cm-2电流密度下可连续放电166 h,性能优于商业Pt/C催化剂.     

MOFs电极材料的制备及其电化学性能

设计了直接利用金属有机骨架化合物(MOFs)材料制备超级电容器电极的实验，并研究了影响其电化学性能的关键因素。先通过一步搅拌加热法制备MOFs材料，并添加碳材料改善MOFs材料的导电性能，进而提升电化学性能；再以X-射线衍射仪、扫描电子显微镜对产物的结构与形貌进行表征，并用循环伏安法、恒流充放电法进行相应的电化学分析。实验结果表明：所制备的MOFs材料为片状结构，加入不同的碳材料后MOFs电极性能得到了明显的提升，其中加入石墨烯的提升效果最为显著；不同浓度的前驱体、石墨烯的用量以及不同的反应条件均会影响MOFs材料的电化学性能。该结果为直接利用MOFs作为电极材料应用于超级电容器中提供参考。     

金属有机框架配合物在药物传输方面的研究进展

金属有机框架材料(metal-organic frameworks,MOFs)因其稳定性好、比表面积大、易于修饰和剪裁等特点,在气体吸附、催化、光学以及生物医学等方面受到广泛关注.近年来,MOFs作为药物传输的一种新材料,具有较高的载药量、生物可降解性及可控性等优点,而被用来传输像布洛芬、5-FU、NO、普鲁卡因胺等的治疗药物.MIL(Materials of Institute Lavoisier),NMOFs(Nanoscale Metal-organic Frameworks),bio-MOFs是MOFs的几个重要分支,重点介绍这几种MOFs材料在药物传输方面的研究进展.     

MOFs材料的制备方法及在传感等方面的应用

金属-有机骨架(MOFs)材料是通过金属离子与有机配体结合而成的配位化合物。MOFs材料具有较大的比表面积、结构可调控、较高的孔隙率和功能化修饰等特点,广泛应用于气体储存、吸附、分离、催化、传感以及医疗等领域。对MOFs材料的制备方法及在传感等方面的应用进行了综述。     

超薄纳米SiC催化材料对氧还原反应催化性能研究

目的:开发高效廉价的氧还原反应催化剂。方法:采用超声剥离法,以商业SiC为原料,成功获得了超薄纳米SiC催化剂,对其形貌进行了表征,并对其催化氧还原(ORR)性能进行研究。结果:超声处理能有效地剥离商业SiC,获得超薄催化剂。超薄纳米SiC催化剂对氧还原反应的起始电位和电流密度均与商业Pt/C催化相近,氧还原反应以4电子路径为主,在较低电位下能获得较大的动力学电流。结论:本实验制备的超薄催化剂,有望作为高效低成本燃料电池的潜在材料。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.