金属钴卟啉负载炭黑在碱性介质中的性质研究

将合成的四甲氧基苯基钴卟啉(CoTMPP)负载于经过双氧水和硝酸预处理且掺杂了MnOx的炭载体上,作为氧还原电催化剂。采用X射线衍射(XRD)、红外透射光谱(IR)、循环伏安曲线(CV)和Koutevky-Levich关系式评价了电催化剂对氧还原反应的电催化性能。结果表明,在碱性介质中,MnOx的掺杂有利于提高催化剂的催化活性,CoTMPP负载于6 mol/L硝酸处理过的炭载体BP 2000上活性较好,同时发现焙烧的最佳温度是900℃。     

炭黑负载四甲氧基苯基钴卟啉(CoMTPP)电催化剂的氧还原性能研究

以四甲氧基苯基钴卟啉(CoMTPP)为活性中心,以炭黑(BP、XC、KB)为载体,制备CoMTPP/炭黑电催化剂,通过UV-Vis、XRD、TEM对其结构进行表征,通过循环伏安曲线和线性扫描伏安曲线研究其氧还原性能,探究其催化氧还原反应的可能机理。结果表明,以KB为载体,在CoMTPP与KB质量比为1∶9时采用一步法负载得到的CoMTPP/KB对氧还原反应的催化活性最高;采用Koutecky-Levich方程计算得到CoMTPP/KB的氧还原反应电子还原数为3.2,表明CoMTPP/KB催化氧还原反应是一个四电子反应和两电子反应共同进行的过程,且更倾向于四电子反应。     

金属卟啉负载炭黑电催化剂氧还原性能

合成了四甲氧基苯基钴卟啉（CoTMPP）和四甲氧基苯基铁卟啉（FeTMPP）配合物,分别负载于经过双氧水和硝酸预处理且掺杂了MnO_x的炭载体,用于质子交换膜燃料电池阴极氧还原反应电催化剂.讨论了不同中心金属离子、不同载体、不同预处理方法和不同焙烧温度对催化剂催化活性的影响.通过旋转圆盘电极技术（RDE）和紫外可见光谱（UV-vis）测试,利用循环伏安曲线（CV）和Koutevky-Levich关系式评价了电催化剂对氧还原反应的电催化性能.研究表明,CoTMPP负载于双氧水处理过的炭载体BP 2000上活性最好,焙烧的最佳温度是900℃,同时发现在载体中掺杂MnO_x并没有达到预期效果.     

炭黑负载MnOx-Pt电催化剂的制备与初步研究

合适的电催化剂材料是质子交换膜燃料电池降低电极反应活化能、加快反应速度、提高电池能量转换效率的关键,尤其是用于阴极氧还原的电催化剂。Vuloan XC-72炭黑进行预处理后作为催化剂载体,采用分步化学沉积方法制备得到了炭黑负载的MnOx-Pt电催化剂。通过ICP、XRD、TEM、CV等物理和电化学手段测试和表征,结果表明;所得到电催化剂中锰氧化物的主要存在形式是隐钾锰矿型MnO2;三种催化剂样品中Mn的质量百分含量均为20％左右,而Pt的质量百分含量在5％左右。该催化剂具有较高的分散度,更高的氧还原起始电位和峰值电位,表现出良好的电催化氧还原性能,可作为质子交换膜燃料电池阴极氧还原的电催化剂;其电化学催化反应机理还有待于进一步深入的研究。     

猪肝为原料制备氧还原电催化剂及其电催化性能

选用价格低廉的生物质猪肝为原料,采用两步热解法和碳负载法制备M-N/C型非贵金属催化剂,考察了热处理温度、混合气体比例及前驱体对催化剂结构和电催化性能的影响.结果表明,热处理温度为1000℃、氮气与氨气体积比为7:3的条件下,二次热解所得催化剂氧还原电催化性能最好.氨气中二次热解改变了催化剂的表面形貌和物相结构,有利于产生更高含量的吡啶型氮,增强了催化剂在碱性溶液中的氧还原电催化活性.黑珍珠2000(BP2000)虽然能显著提高一次热解催化剂的活性,但由于其在氨气中的反应活性不如热解猪肝所得碳材,在氨气二次热解中对催化剂活性反而有不利影响.     

掺氮碳基材料在费托合成反应中的应用

氮掺杂是一种对碳材料结构和性质进行修饰的重要方法。本文主要介绍了碳基材料掺氮的主要方法(即直接合成法和后处理法)及所得掺氮碳基材料的性质。重点综述了近年来掺氮碳基材料在制备费托合成钴基和铁基催化剂领域中的应用,进一步阐述了掺氮碳基材料作为新型费托合成催化剂载体所具有的主要优点:载体表面含氮基团具有锚定作用可提高金属活性组分分散度,同时,氮的掺杂不仅能够有效地提高催化剂还原度,而且富电子的氮物种可促进CO解离,从而有利于提高催化剂费托合成反应性能。在此基础上,本文也分析了掺氮碳基材料的合成和催化应用方面所存在的问题。     

锌空气电池双功能阴极催化剂研究进展

可充电锌空气电池(ZAB)被认为是具有前景的储能设备之一.阴极氧还原反应和氧析出反应(ORR和OER)动力学缓慢,限制ZAB的实际应用,开发出高活性催化ORR/OER双功能阴极电催化剂尤为重要.综述了非贵金属双功能阴极电催化剂,包括无金属碳材料催化剂、过渡金属催化剂和过渡金属-氮掺杂碳材料组合催化剂,讨论几种催化剂催化...     

伯克利和阿贡实验室发现燃料电池用高活性新类别纳米催化剂

正目前,下述两种反应的最佳电催化剂由铂纳米颗粒分散在碳上组成。铂(Pt)对于燃料电池(金属空气电池)中的阴极氧还原反应(ORR)以及碱性电解槽中的氢进化反应(HER)均是高效的电催化剂。美国伯克利和阿贡国家实验室的研究人员领导的团队于2014年2月底宣布,发现了一种新的双金属纳米催化剂,可应用于燃料电池和水-碱电解槽,其效率更高,成本更低,其活性比美国能源部设     

亚胺COFs在电催化领域的应用研究进展

亚胺共价有机框架材料(COFs)作为一种新兴的多孔晶体聚合物,具有规整的孔结构、高的比表面积、可调的抗衡离子、丰富的活性位点等.在燃料电池中,亚胺COFs对于制备高效电催化剂和促进能量转换至关重要.首先介绍了亚胺COFs基电催化剂的优势;然后综述了其作为电催化剂在还原CO2、析氧反应、析氢反应、氧还原反应等领域的应用;最后讨论了亚胺COFs高性能电催化剂当前的挑战和未来前景.     

多孔碳材料的制备及其金属磷化物氧还原性能研究

多孔碳材料及其金属磷化物在电催化氧还原反应中具有广阔的应用前景。以三聚氰胺为碳源和氮源，磷酸氢二铵为磷源，制备具有超高比表面积的氮、磷共掺杂的中空碳纳米壳，通过调节磷源实现了多孔高比表面碳材料的制备。将三聚氰胺、磷酸氢二铵和铁前驱体复合，制备氮、磷共掺杂的石墨碳包裹的磷化铁纳米颗粒。石墨碳层和磷化铁之间存在电子相互作用，内部的磷化铁向外层石墨碳转移电子，这种界面相互作用大大提高了催化剂氧还原（ORR）活性，半波电位高达0.9 V。同时，包裹的碳层起到保护磷化铁（FeP）免受氧化和溶解的作用，催化剂表现出较好的稳定性。     

A Wasted Material,Duck Blood,as a Precursor of Non‐Precious Catalyst for the Oxygen Reduction Reaction

Searching for non‐precious electrocatalysts with high performance to replace the expensive Pt‐based electrocatalysts for oxygen reduction reaction (ORR) is a key issue in the industrial‐scale application of fuel cells. In this study, we have reported the synthesis of an iron doped N‐containing carbon materials, derived from duck blood, a wasted material in the duck meat production, as a novel and cost‐effective catalyst in ORR. The as‐prepared electrocatalysts were characterized by means of powder X‐ray diffraction, scanning electron microscopy, Raman spectroscopy and X‐ray photoelectron spectrometer. In 0.1 mol L⁻¹ KOH solution, the ORR onset potential and the half‐wave potential for the iron doped N‐containing carbon materials are 33 mV and –120 mV respectively, which are close to those of commercial Pt/C (20 wt%). In addition, the iron doped N‐containing carbon materials exhibit excellent tolerance to methanol crossover, which makes it a promising electrocatalyst for ORR in fuel cell.     

Carbon as catalyst and support for electrochemical energy conversion

Carbon has unique characteristics that make it an ideal material for use in a wide variety of electrochemical applications ranging from metal refining to electrocatalysis and fuel cells. In polymer electrolyte fuel cells (PEFCs), carbon is used as a gas diffusion layer, electrocatalyst support and oxygen reduction reaction (ORR) electrocatalyst. When used as electrocatalyst support, amorphous carbonaceous materials suffer from enhanced oxidation rates at high potentials over time. This drawback has prompted an extensive effort to improve the properties of amorphous carbon and to identify alternate carbon-based materials to replace carbon blacks. Alternate support materials are classified in carbon nanotubes and fibers, mesoporous carbon, multi-layer graphene (undoped and doped with metal nanoparticles) and reduced graphene oxide. A comparative review of all these supports is provided. Work on catalytically active carbon hybrids is focused on the development of non-precious metal electrocatalysts that will significantly reduce the cost without sacrificing catalytic activity. Of the newer electrocatalysts, nitrogen/metal-functionalized carbons and composites are emerging as possible contenders for commercial PEFCs. Nitrogen-doped carbon hybrids with transition metals and their polymer composites exhibit high ORR activity and selectivity and these catalytic properties are presented in detail in this review.     

双功能yolk-shell钴@钴氮碳掺杂氧电极催化剂

以ZIF-67为模板,通过表面原位聚合多巴胺,与金属Co²⁺发生强烈螯合,释放出有机配体,得到中空的金属-有机结构材料（Co-PDA）。通过900℃高温处理得到类似蛋黄（yolk-shell）结构的金属氮掺杂碳材料（Co@Co-N/C）。这种特殊结构的材料具有优异的氧还原（ORR）和析氧反应（OER）电催化活性,在0.1 mol/L KOH电解液中,其ORR的半波电位为0.81 V,Tafel斜率为60 mV/dec;在电流密度为10 mA/cm²时,其OER过电位为390 mV,Tafel斜率为71 mV/dec,总的氧电极催化活性为0.82 V,是一种优良的双功能氧电极催化剂。     

氮掺杂科琴黑碳材料的制备及 电催化氧还原性能研究

氮掺杂碳材料是一种有应用前景的电催化氧还原催化剂。以尿素和三聚氰胺作为氮源,在氮气气氛下高温焙烧,制得两种氮掺杂科琴黑碳材料并将其用于电催化氧还原反应。使用X射线衍射仪（XRD）、X射线光电子能谱仪（XPS）、场发射扫描电子显微镜（FESEM）、比表面物理吸附分析仪等对氮掺杂前后的科琴黑的结构和形貌进行了分析。结果表明：氮掺杂之后科琴黑仍保持石墨结构,其形貌和比表面积均无明显改变。在XPS谱图上,氮掺杂后科琴黑上存在氮元素,其中以三聚氰胺为氮源比以尿素为氮源更容易得到吡啶氮。通过循环伏安法和线性扫描伏安法研究了3个样品的电催化氧还原性能。结果表明：氮掺杂能明显提高科琴黑的电催化氧还原性能,未掺杂的 科琴黑（AC）的半波电位为0.746 V,而以尿素和三聚氰胺为氮源掺杂后的科琴黑碳材料的半波电位分别提高到了 0.756 V（尿素-N/AC）和0.786 V（三聚氰胺-N/AC）。     

Functionalized-carbon nanotube supported electrocatalysts and buckypaper-based biocathodes for glucose fuel cell applications

The preparation and testing for electrocatalytic activity of functionalized carbon nanotube (f-CNT) supported Pt and Au–Pt nanoparticles (NPs), and bilirubin oxidase (BOD), are reported. These materials were utilized as oxygen reduction reaction (ORR) cathode electrocatalysts in a phosphate buffer solution (0.2 M, pH 7.4) at 25 °C, in the absence and presence of glucose. Carbon monoxide (CO) stripping voltammetry was applied to determine the electrochemically active surface area (ESA). The ORR performance of the Pt/f-CNTs catalyst was high (specific activity of 80.9 μA cm_Pt⁻² at 0.8 V vs. RHE) with an open circuit potential within ca. 10 mV of that delivered by state-of-the-art carbon supported platinum catalyst and exhibited better glucose tolerance. The f-CNT support favors a higher electrocatalytic activity of BOD for the ORR than a commercially available carbon black (Vulcan XC-72R). These results demonstrate that f-CNTs are a promising electrocatalyst supporting substrate for biofuel cell applications.     

Analysis of forming process of nitrogen-doped carbon catalyst derived from Fe 1,10-phenanthroline compound and its oxygen reduction reaction activity

The pyrolysis behavior of iron 1,10-phenanthroline compound, the change of crystalline structure of iron in the iron 1,10-phenanthroline compound, and nitrogen chemical state of nitrogen doped carbon catalyst derived from iron 1,10-phenanthroline compound were investigated to clarify the process of improvement of oxygen reduction reaction (ORR) activity on nitrogen-doped carbon catalyst by TGA, EGA-MS, HT-XRD, XRD, and XPS technique. The ORR activity drastically improved at a synthesis temperature of 700 °C, and was the highest at a synthesis temperature of 800 °C. But the ORR activity significantly dropped at a synthesis temperature of 900 °C. This low ORR activity of NC-900 is probably due to the increase of quaternary nitrogen ratio with progression of excessive carbonization, and the quaternary nitrogen to pyridine-like nitrogen ratio might be an important factor for improvement of the ORR activity.     

Electrocatalytic activity of nitrogen doped carbon nanotubes with different morphologies for oxygen reduction reaction

Nitrogen doped carbon nanotubes (NCNTs) were synthesized by a single step chemical vapor deposition technique using either ferrocene or iron(II) phthalocyanine as catalyst and pyridine as the carbon and nitrogen precursor. Variations in surface morphology and electrocatalytic activity for oxygen reduction reaction (ORR) were observed between the NCNTs synthesized using different catalysts. The structural and chemical characterizations were carried out using transmission electron microscopy (TEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The electrochemical activity of NCNTs was evaluated with rotating ring disc electrode (RRDE) voltammetry. Structural characterization suggested more defects formed on the NCNTs synthesized from ferrocene (Fc-NCNTs) which led to a rugged surface morphology compared to the NCNTs synthesized from iron(II) phthalocyanine (FePc-NCNTs). Based on the RRDE voltammetry study, Fc-NCNTs demonstrated much higher activity for ORR than FePc-NCNT. Evidences from the structural and chemical characterizations illustrate the potential impact of catalyst structure in shaping the surface structure of NCNTs and the positive effect of surface defects on ORR activity. These results showed that potential improvements on ORR activity of NCNTs could be achieved by tailoring the surface structure of NCNTs by using catalysts with different structures.     

Improved carbon nanostructures as a novel catalyst support in the cathode side of PEMFC: a critical review

Carbon supported platinum nanoparticles are extensively used as electrocatalysts in proton exchange membrane fuel cells (PEMFCs). The stability and performance of the electrocatalyst strongly depends on the deposition method and properties of the carbon support. Carbon black is commonly used as support for platinum (Pt–C) due to its low cost and high availability, good electrical performance, and relatively high surface area. However, carbon corrosion, Ostwald ripening, and Pt dissolution have been recognized as the main cause for low durability of this electrocatalyst under high potential conditions. As a result, the necessity for promising supports with higher stability is inevitable. It has been reported that carbon nanomaterials with higher mesoporosity, surface area, electrical conductivity, stability and suitable anchoring site are promising supports under harsh oxidizing condition of PEMFCs. This review is devoted to the development of recent advances in novel carbon nanomaterials as catalyst support, such as carbon nanotubes, carbon nanofibers, graphene, mesoporous carbon, and etc., for the oxygen reduction reaction (ORR) in PEMFCs. Moreover, the main challenges such as low activity, poor durability, and high cost, are addressed and discussed. The performance and obstacles of these carbons associated with different metal catalyst deposition methods are highlighted.     

Highly efficient metal-free phosphorus-doped platelet ordered mesoporous carbon for electrocatalytic oxygen reduction

Platinum-free electrocatalysts especially, various heteroatom-doped carbon nanostructures have attracted particular attraction as plausible solution for commercializing fuel cell technology. In this direction, novel phosphorus-doped platelet ordered mesoporous carbon (P-pOMC) is developed for the first time as metal-free electrocatalyst for alkaline oxygen reduction reaction. The P-pOMC is synthesized by nanocasting method using platelet ordered mesoporous silica as template. Various characterizations reveal that the P-pOMC materials have covalently bound P atoms with carbon framework for facilitation of oxygen reduction reaction (ORR) and also have very high surface area with uniform distribution of short mesoporous channels for unhindered mass transfer. Combination of P doping and excellent surface properties empowers the newly-developed P-pOMC catalyst to show high ORR activity nearly equal to that of state of the art Pt catalyst along with superior long-term stability and excellent methanol tolerance.