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1.
过渡族金属基二维纳米材料作为电催化析氧反应(oxygen evolution reaction, OER)催化剂具有巨大的潜力。通过原位电沉积法,在泡沫镍基底表面制备了二维层状镍铁双氢氧化物(NiFe-LDH)和氧硫化钼Mo(OS)x纳米片异质结构。NiFe LDH/Mo(OS)x电极在1 M KOH溶液中表现出优异的OER性能和长效稳定性,在10 mA/cm2电流密度下过电势仅为220 mV。在100、500 mA/cm2的高电流密度下,也能达到253、304 mV的低过电势。研究结果表明,NiFe-LDH/Mo(OS)x电极优异的OER性能归因于Mo(OS)x和NiFe LDH的协同作用,极大地促进了Fe2+向Fe3+活性物质的转化,并促进了氧空位的形成。这种协同制备方法为合理构建和设计异质结构电催化剂,实现高效的水分解提供了帮助。  相似文献   

2.
采用共沉淀法制备出ZIF-8@ZIF-67/LDH纳米复合物。使用扫描电子显微镜(scanning electron microscope,SEM)、X射线衍射仪(X-ray diffractometer,XRD)、拉曼光谱仪(Raman spectrometer,Raman)和X射线光电子能谱仪(X-ray photoelectron spectrometer,XPS)对复合物的表面形貌、晶体结构和组成进行了表征。采用电化学工作站进行析氧反应(oxygen evolution reaction, OER)、析氢反应(hydrogen evolution reaction, HER)以及水分解性能测试。结果表明,该复合物在1 mol/L的KOH水溶液中,所需的OER过电势为329 mV (η10);HER过电势为175 mV (η10);在双电极体系中,电流密度达到10 mA/cm2,完全水分解所需的电压为1.761 V。经过12 h的HER(-20 mA/cm2)计时电位稳定性测试,末电势较初始电势只下降了6 mV左右。结合相关表征分析,催化剂的高活性得益于大的电化学活性面积的核壳结构,为反应提供丰富的活性位点,通过ZIF-8@ZIF-67和LDH的共同效应,ZIF-8@ZIF-67/LDH表现出良好的OER和HER活性以及优异的稳定性。  相似文献   

3.
为深入了解催化剂中晶体缺陷对析氧反应(oxygen evolution reaction, OER)催化性能的影响,运用第一性原理研究S空位对Ni3S2(101)晶面的影响,并通过O原子补偿空位提高催化剂的催化活性.计算结果表明:空位的引入有利于OER过程中含氧中间体的吸附,但却严重阻碍了其解吸附,导致催化活性降低;当O原子通过替位掺杂对S空位进行补偿时,可有效改善催化剂活性位点的解吸附能力,使缺陷体系的催化活性得到大幅提高.本文所得结果为设计高效的Ni3S2基二维电催化剂提供了参考.  相似文献   

4.
近年来,能源危机、环境污染等问题导致了人们对开发高效清洁能源的迫切需求。氢气作为一种具备广泛应用前景的可替代能源,可通过电解水制备。然而,电解水制氢过程主要受制于阳极缓慢的析氧反应(oxygen evolution reaction,OER)过程。镍铁基层状双氢氧化物(nickel-iron layered double hydroxide,NiFe-LDH)由于其具备独特的层状结构、成本低廉、含量丰富且催化性能优异等特点,近年来被广泛研究。综述了通过晶格掺杂、空位缺陷和表面修饰对NiFe-LDH化合物进行改性的最新研究进展,简要讨论了改性NiFe-LDH化合物研究过程中遇到的挑战和前景。  相似文献   

5.
以金属有机骨架(metal-organic frameworks, MOFs)化合物为前驱体, 通过退火、硫化等后续处理方法成功制备了由 NiFe2O4 纳米棒与 Co9S8 空心球组装而成的杂化纳米结构. 该复合催化剂因具有较大的比表面积以及各组分间强力的协同作用, 在电催化析氧反应(oxygen evolution reaction, OER)中表现出了优异的催化活性. 在 1 mol/L KOH 电解质中, 当电流密度达到 10 mA/cm2 时, 仅需 290 mV 的过电位, 且 Tafel 斜率仅为 63.02 mV/dec. 此外, 1 000 次循环伏安(cyclic voltammetry, CV)测试后仍然具有良好的催化活性, 表明该复合催化剂具有优异的稳定性. 研究成果不仅为设计廉价、高效且稳定的析氧催化剂提供了设计思路, 也为其他新型纳米复合材料的合成和应用奠定了基础.  相似文献   

6.
本工作通过溶剂热法制备了 CoFe-B-P 纳米颗粒,并考察其电化学析氧性能 . 所 制备催化剂的形貌结构和组分通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍 射仪(XRD)、X射线光电子能谱(XPS)和电感耦合等离子体发射光谱(ICP-OES)等手段进行表 征 . 研究发现,当 Co/Fe 的摩尔比为 4∶1 和 NaH2PO2·H2O 的加入量为 2.0 mmol 时,所制备 Co4Fe1-B-P 催化剂展现了最优异的催化 OER 性能,在电流密度为 10 mA cm?2 时的过电位为 285 mV,较小的塔菲尔斜率(52.70 mV/dec),并且在1.0 M KOH电解液中连续测试20 h后仍具 有优异的稳定性 . 所制备催化剂 OER 活性的提高主要归因于过渡金属与非金属之间的协同 作用.  相似文献   

7.
过渡金属间隙化合物(transition metal interstitial compounds, TMICs)具有独特的电子结构、高导电性、优异的化学稳定性,可作为可再生能源转化反应中Pt基催化剂的替代电催化剂.从这个角度出发,综述了TMICs在合成和电催化性能方面的研究进展,主要归纳了TMICs在析氢反应、析氧反应、氧还原反应、直接液体燃料电池阳极反应等方面的催化性能.此外,简述了TMICs电催化剂实际应用于能量转换设备中的潜力,这对开发高效稳定的电化学能量转换设备具有指导意义.  相似文献   

8.
氧还原反应(oxygen reduction reaction,ORR)是能量转换和储存系统的关键电极反应。目前,贵金属基材料,如铂和钯,是ORR最有效的催化剂,但其地球储量稀少、价格昂贵,且抗甲醇和CO性能差。因此,开发新型、低成本、高性能的氧还原电催化剂对能源转化和储存具有重要意义。综述了近年来非贵金属钴(Co)基氧还原电催化材料的研究进展及其性能调控策略,分为Co合金、Co-N-C、Co纳米粒子、Co基氧化物、Co基磷化物和Co基硫化物等多种形式,并对未来开发低成本、高性能的氧还原催化剂进行了展望。  相似文献   

9.
Co与过渡金属合金化是提高析氧催化剂反应活性的一种有效策略.Co与同周期的Fe元素合金化,其电子微扰作用有利于增强Co活性中心的析氧效果.本研究采用电沉积法制备Fe0.5Co0.5合金,分析其微观形貌、成分、结构和折氧性能,研究前驱溶液配比浓度与最终催化剂性能的关系.通过表面微观调控,Fe0.5Co0.5合金在0.1 mol/L KOH溶液中的过电位为345.3 mV,塔菲尔斜率为114 mV/dec,极大地提升了单质Co的析氧催化剂反应动力学活性.其耐久性测试结果表明,经过7200 s的长时应用后其电流密度仍然高达5.2 mA/cm2.  相似文献   

10.
化石燃料的应用带来了温室效应等环境问题。氢能源被认为是代替化石燃料的清洁能源之一。电解水制氢对环境不产生二次污染,因此,探索用于析氢反应的高效电催化剂是人类积极面对的课题。金属有机框架(Metal Organic Framework,MOF)基材料在电解水过程中具有良好的催化性能,有望代替贵金属电极。着重综述了MOF基材料的析氢反应(Hydrogen Evolution Reaction,HER)和析氧反应(Oxygen Evolution Reaction,OER)性能,总结分析了当前设计此类MOF基电极材料的新思想。  相似文献   

11.
Transition metal phosphides have been recognized as promising electrocatalysts for oxygen evolution reaction(OER) due to their low cost and high activity. However, the insufficient exposed active region limited the OER performance. Recently, the introduction of sacrificial dopants has been considered an effective strategy to enlarge the surface area. Herein, the Zn dopants are introduced in NiFe phosphide(NiFeZnP) nanosheet, which work as the sacrificial dopants to generate more exposed active N...  相似文献   

12.
Developing efficient oxygen evolution reaction(OER) electrocatalysts is of great importance for sustainable energy conversion and storage. Ni-based catalysts have shown great potential as OER electrocatalysts, but their performance still needs to be improved. Herein, we report the multiple metal doped nickel nanoparticles synthesized via a simple oil phase strategy as efficient OER catalysts. The FeMnMoV–Ni exhibits superior OER performance with an overpotential of 220 mV at 10 mA cm-2  相似文献   

13.
Designing advanced electrocatalysts for the oxygen evolution reaction (OER) is of great significance owing to its crucial role in facilitating the production of clean hydrogen energy via water splitting. To date, it has been widely accepted that a pre-oxidation process with the in-situ generation of the catalytically active high-valence metal sites is essential for promoting the OER behavior of most transition-metal-based OER catalysts, or more felicitously speaking, pre-catalysts. Hence, exploring such pre-catalysts with high pre-oxidation reactivity is of high promise. Herein, we proposed the dual elemental modulation in the cationic and anionic sites of the multi-metal Prussian blue analogue (PBA) pre-catalysts, resulting in promoted OER behavior benefitted from the efficient pre-oxidation ability as well as the multi-metal synergy. Detailed investigations indicate that the Co-containing multi-metallic cations and mixed FeIIICoIII cyanide anions in NiCuCoII–FeIIICoIII PBA (denoted as NiCuCoII–FeIIICoIII) are beneficial to OER catalysis owing to the high intrinsic activity guaranteed by the local Co3+ active sites as well as the optimal multi-metal synergy. After the facile pre-oxidation process, additional high-valence Ni, Cu and Fe ions can be in-situ formed and serve as the active sites, thereby resulting in significantly improved OER behavior. For example, the OER current density of NiCuCoII–FeIIICoIII exhibits 1.81 times enhancement even after 72 ?h continuous OER catalysis, and the required overpotential for 10 ?mA ?cm?2 reduces from 288 ?mV for the fresh pre-catalyst to a remarkable record of 251 ?mV after the pre-oxidation-induced activation, making the optimal PBA-based catalyst a promising candidate for efficient and durable water electrolysis.  相似文献   

14.
氢能具有高能量密度、绿色可持续的优点,是人类社会的理想能源。电解海水制氢是未来氢能产业的战略方向,其中阴极析氢催化剂的活性和稳定性对电解海水制氢的发展至关重要。贵金属铂虽具备优异的析氢催化性能,但价格昂贵、资源有限,限制了其大规模应用。因此,对非贵金属催化剂的研究备受关注。从析氢反应原理入手,介绍了过电位、塔菲尔斜率、法拉第效率、比活性和质量活性等评价催化性能的几个重要参数,综述分析了多种非贵金属催化剂作为电解海水制氢阴极催化剂的研究现状,指出了目前电解海水制氢面临的问题,认为未来非贵金属催化剂规模化电解海水阴极析氢研究应从以下几方面开展:1)设计高活性和稳定性的非贵金属催化剂;2)优化非贵金属催化剂的制备工艺;3)利用先进测试表征手段辅助构建反应模型;4)深化理论计算机理方面的研究。  相似文献   

15.
To meet the sharp increase in demand for clean and renewable energy, it is necessary to develop new energy-conversion and storage technologies, such as proton exchange membrane fuel cells (PEMFCs) and metal-air/oxygen batteries (MABs). Due to the sluggish reaction kinetics of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in the cathodes of PEMFCs and MABs, significant amounts of precious metal catalysts need to be used, driving up the cost of fuel cells and MABs and thereby hindering their commercialization on a large scale. Transition metal and nitrogen co-doped carbonaceous catalysts (M/N/C) have high catalytic activity towards the ORR and OER once the catalysts are modified with certain promoters/additives. In addition, M/N/C catalysts can be prepared from abundant, inexpensive materials, making their cost negligible compared with precious metal catalysts, a development that would efficiently decrease the cost of PEMFCs and MABs. In last decade, numerous researchers have attempted to realize these applications of M/N/C catalysts, and some exciting results have been achieved, making these promising replacements for precious metal catalysts. However, some serious problems and significant challenges remain. In this paper, we review the research on the application of M/N/C analogue catalysts in PEMFCs and MABs in the last 10 years, indicate the remaining challenges, and suggest the future research directions.  相似文献   

16.
金属基氧电极材料催化机理研究进展   总被引:2,自引:2,他引:0  
燃料电池作为一种高效、无污染的能源转换器件,受到广泛关注.其阴极氧还原反应是决定电池性能最重要、最关键的因素之一,也是制约其商业化的关键瓶颈因素之一.因此,研究和开发高效氧还原催化剂及其催化机理,对于燃料电池的发展和商业化进程具有十分重要的意义.在简要介绍燃料电池的基础上,综述了近年来金属基氧还原电极材料催化氧还原反应的机理,金属基氧还原电极材料包括Pt催化剂、Pt-M催化剂、杂原子掺杂碳载金属类催化剂等,总结了提高催化活性和稳定性、降低催化剂制备成本和催化剂制备工艺等方面所取得的研究结果,并指出了各类催化剂目前尚待解决的问题和发展方向.  相似文献   

17.
Cu2O is an ideal template material for the preparation of transition metal hydroxide/oxyhydroxides with oxygen evolution reaction (OER) enhanced catalytic performance. Here, inspired by Pearson's principle, Cu2O wires were prepared and used as a sacrificial template to prepare Ni(OH)2·0.75H2O hollow tubes (Ni(OH)2 HTs) with highly improved surface roughness. Benefiting from unique structural advantages, the Ni(OH)2 HTs showed excellent catalytic activity, rapid kinetics and a long-term stability as the OER catalyst, where an overpotential of only 207 ?mV was required to drive a current density of 10 ?mA ?cm?2, an ideal kinetics with a Tafel slope as 79.8 ?mV dec?1 was calculated, and no obvious attenuation in chronoamperometry was discovered after operation for 24 ?h. This paper provides a novel template-assisted strategy to prepare high-performance transition metal-based OER catalysts possessing hollow and tubular structures.  相似文献   

18.
氢燃料电池是一种将化学能直接转换为电能的能量转换装置,具有转换效率高、噪声低、无污染、原料多样且用途广泛等优点,但其阴极氧还原反应(oxygen reduction reaction,ORR)动力学缓慢,极大地限制了其大规模应用与发展.因此,研发高效、耐用兼具经济性的ORR电催化剂是当前研究热点之一.在众多科研工作者的努力下,关于ORR电催化剂的研究工作已取得了许多重要突破性进展.本综述系统介绍了ORR反应机制和目前3种主流类别的ORR电催化剂(贵金属、非贵金属、碳基)的研究进展,着重分析了不同催化剂体系的性能与优缺点,并探讨了高性能ORR电催化剂的合成策略及其未来的发展方向.   相似文献   

19.
Combined with air annealing, rutile-structured IrO 2 nanoparticles with various sizes were prepared using colloidal method. The nanoparticles were used as the electrocatalysts for the oxygen evolution reaction (OER) in acidic media, and their grain size effect was studied. The results show that with the increase in annealing temperature, the grain size of the catalyst increases, and the voltammetric charges (the electroactive areas) and apparent activity for the OER decrease. The relationship between the intrinsic activity and the annealing temperature exhibits a volcano-type curve and the catalyst annealed at 550 ℃ achieved the best result.  相似文献   

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