基于过渡金属电催化析氢催化剂的研究进展

随着人口快速增加,开发可持续能源已经成为当今世界的首要任务之一。氢气被认为是一种无污染、可再生的新能源,可以代替化石能源。氢气可以由电解水的电催化析氢半反应获得。传统的电催化析氢催化剂主要由贵金属构成,而贵金属稀少,价格昂贵,不适合大规模工业制氢。探索高效的非贵金属电催化析氢反应催化剂十分必要。基于过渡金属开发的电催化析氢反应催化剂引起广泛关注,综述基于过渡金属电催化析氢反应催化剂的研究进展,概述电解水原理,讨论基于过渡金属化物的电催化析氢反应催化剂材料的制备方法,包括硫化物、硒化物、碳化物、氮化物、磷化物及其复合物。探讨增强催化剂电催化析氢活性的方法及基于非贵金属电催剂材料面临的挑战和前景展望。     

苏州纳米所开发出高性能HER和ORR非贵金属催化剂

<正>随着能源危机和环境污染的日益加剧,开发新型的清洁能源刻不容缓。其中涉及电化学过程的析氢反应(HER)和氧还原反应(ORR)是两种最具实际应用前景的能源转换和存储方式。因此,设计高性能的HER和ORR的电催化剂对提高电化学能源转换和存储性能尤为重要。目前,Pt及其合金是HER和ORR电催化     

中空碳基材料在电解水中的研究进展

氢能所具有的清洁、高能量密度特点，使其成为一种未来的理想能源。相较于石油、天然气等的热解制氢技术，利用可再生清洁能源进行电催化分解水制氢具有高效和清洁无污染的特点，且获得氢气产物纯度高，具备大规模发展的潜力。而在大规模水电解过程中，电催化剂是不可或缺的元素之一。它能有效地加速电解水在阴阳两极反应的动力学过程。传统的贵金属基催化剂具有良好的电催化析氢、析氧活性，但成本高昂、储量稀缺，从而限制了其规模化地推广及应用。开发新型高效廉价的非贵金属基电催化剂已成为时下研究热点。中空碳基纳米材料集成了中空材料和碳基材料的优势，作为电催化剂，在电解水方面有着潜在的应用价值。本文总结了近年来微纳米结构碳基中空材料作为新型电解水催化剂的研究进展，介绍了高效碳基中空析氧/析氢催化剂的设计原则和相应的设计策略，并对开发持久高效的中空碳基电解水催化剂进行了总结和展望。     

非贵金属双活性位点碱性电催化分解水研究进展

随着化石能源的枯竭和环境污染问题的加剧,人们正在寻求新的能源以取代传统化石能源。氢能作为一种清洁、可再生能源吸引了全世界研究人员的广泛关注。通过电解水制氢是一种符合可持续发展的实用性技术,其所耗电能可由风力发电,太阳能电池等所提供。在原子层面研究与设计具有多重反应位点的新型电催化剂是提高碱性析氢反应的重要手段。本文阐述了碱性电催化析氢中非贵金属双活性位点的作用和意义。     

单原子位点催化剂及其电催化应用研究进展

单原子位点催化剂作为新兴类别,由于具有接近100%的高效原子利用率,出色的活性、选择性和稳定性等优异特性,受到广泛的关注和研究。本文综述了单原子位点催化剂的最新研究成果及在电催化领域的应用。详细介绍了单原子位点催化剂的制备方法,包括“自下而上”合成策略中的共沉淀法、电化学沉淀法、原子层沉积法、光化学法和原子约束法等,“自上而下”合成策略中的高温原子迁移捕获法、高温热解法和悬挂键捕获法。分析了用于表征单原子位点催化剂的高角环形暗场透射扫描显微镜和X射线吸收光谱表征技术,进行单原子位点催化剂理论计算的密度泛函理论（DFT）和第一性原理。在电催化领域的应用主要包括氧还原反应（ORR）、氮还原反应（NRR）、CO₂还原反应（CO₂RR）、氢析出反应（HER）和氧析出反应（OER）。最后指出目前单原子位点催化剂存在无法大规模生产和催化机制不清晰等问题并给出相关建议,展望了单原子位点催化剂的发展前景,指出创新制备方法以实现稳定型单原子位点催化剂的大规模制备及工业应用,利用先进表征技术进一步明确单原子位点催化剂催化机制是未来发展的方向。     

NiFeSx/NF纳米片的制备及电解水性能研究综合教学实验设计

为了开阔学生的科学视野,加深学生对于催化剂以及电催化反应的理解,本文设计了在泡沫镍(NF)上原位生长硫化镍铁(NiFeS_x/NF)纳米片的实验,研究了硫化镍铁结构与电解水性能之间的关系。结果表明,NiFeS_x/NF可以作为一种高性能的析氢反应(HER)和析氧反应(OER)双功能电催化剂,具有优异的催化活性和稳定性。该实验将科研工作与学生实验教学相结合,培养了学生的科学精神、创新思维意识和创新能力,激发了学生的科研兴趣。     

电催化分解氨制氢研究进展

氢能作为一种理想的能源载体之一，近些年来受制于储存和运输的难题并未大规模发展。但随着电催化技术的成熟，在温和条件下，通过电催化分解含氢介质的制氢路线或将具备规模化开发清洁能源的潜力。氨(NH₃)具有高储氢密度(17.6%，质量分数)、运输便利、无碳等优点，被认为是合适的储氢介质之一。电催化分解氨的过程主要包括析氢反应(hydrogen evolution reaction， HER)和氨氧化反应(ammonia oxidation reaction， AOR)。重点综述了阳极电催化分解氨的反应机理及AOR催化剂的研究现状，对氨氧化技术的发展和应用进行了总结和展望，可为开发具有更高活性、稳定性的AOR催化剂和“以氨制储氢”的发展路线提供思路和指导。     

Ni/CrN高效电催化剂的制备及其析氢催化性能

氢能是一种具有高能量密度的清洁能源,如何有效的开发绿氢技术是当前社会首要解决的问题,而研发高效稳定的电解水产氢技术的电催化剂是一种可行性的方式,对促进氢能经济的发展具有重要的意义。通过水热-高温热解两步法合成了一种氮化铬支撑镍纳米颗粒的催化剂(Ni/CrN)。利用XRD、XPS、SEM以及TEM等测试手段对催化剂的形貌及结构进行表征,并在碱性环境下对催化剂进行电催化析氢性能的研究。结果表明,Ni/CrN形成了具有珊瑚状的微观结构,优化了电子结构,并且表现出了优异的析氢反应(HER)催化性能,在10 mA/cm²的电流密度下,Ni/CrN催化剂仅有66 mV的过电位和47 mV/dec的Tafel斜率,十分接近商业的Pt/C催化剂的析氢性能。在10 mA/cm²电流密度的循环稳定性测试中,Ni/CrN表现出比商业Pt/C电极更优越的催化稳定性。     

合肥研究院非贵金属电催化剂有机合成及性能研究获进展

正近期,中国科学院合肥物质科学研究院固体物理研究所环境与能源纳米材料中心研究人员在非贵金属催化剂电催化氧化二级醇到二级酮研究中取得新进展。相比析氢反应(HER),析氧反应(OER)的过电位较高,产物(氧气)附加值较低。若能通     

CoSe2@NF双功能电催化剂用于高效碱性全解水

开发用于水分解的高效稳定、低成本非贵金属电催化剂，特别是在同一电解质中对阴极的析氢反应(HER)和阳极的析氧反应(OER)都具有高效作用的电催化剂是一项挑战。以六水合硝酸钴、尿素、氟化铵和硒粉为原料，采用水热和高温固相法在镍网上原位构筑了CoSe2@NF，采用XRD、XPS、SEM和TEM对CoSe2@NF进行物相分析和形貌表征，并在碱性电解液中对CoSe2@NF的电催化析氧和析氢性能进行了测试。结果表明，表面粗糙的串珠状纳米线结构极大地增加了CoSe2有效活性位点的数量。该催化电极在OER和HER中均表现出高而稳定的催化活性。将CoSe2@NF作为全解水槽的阴阳极，在1.6 V槽电压下即可产生10 mA/cm2的电流，并可在1.7 V的电压下稳定运行100 h。这项研究为全解水提供了一种经济有效的解决方案.     

Molybdenum-based electrocatalysts with nanostructured supports for hydrogen evolution reaction

Electrochemical water splitting is one of the most efficient ways to yield H₂ fuel due to its renewability and environmental friendliness. For minimizing the energy loss during the electrocatalytic hydrogen evolution reaction (HER), as a crucial half-cell reaction of electrochemical water splitting, researchers are seeking for suitable electrocatalysts, which can significantly decrease the overpotential and consequently promote the reaction rate and total cell efficiency. Among the noble-metal free HER catalysts, Mo-based electrocatalysts have been reported to possess excellent electrocatalytic activity and long-term durability in terms of the HER process. Recently, in order to further improve the reaction rate of HER, nanostructured supports for Mo-based catalysts were designed, which not only increase active sites but also contribute to alleviating the overpotential. Herein, an overview is presented of recent research progress on Mo-based electrocatalysts with nanostructured supports for the HER. It starts with summarizing the fundamentals of HER and recent progress of Mo-based electrocatalysts. Subsequently, the design and synthesis of nanostructures, electrochemical performance, and the related mechanisms for Mo-based electrocatalysts with nanostructured supports are discussed. Finally, the future opportunities and challenges are highlighted for the development of the Mo-based electrocatalysts from the points of view of both fundamental understanding and practical application.     

Graphene-reinforced metal-organic frameworks derived cobalt sulfide/carbon nanocomposites as efficient multifunctional electrocatalysts

Developing cost-effective electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is vital in energy conversion and storage applications. Herein, we report a simple method for the synthesis of graphene-reinforced CoS/C nanocomposites and the evaluation of their electrocatalytic performance for typical electrocatalytic reactions. Nanocomposites of CoS embedded in N, S co-doped porous carbon and graphene (CoS@C/Graphene) were generated via simultaneous sulfurization and carbonization of one-pot synthesized graphite oxide-ZIF-67 precursors. The obtained CoS@C/Graphene nanocomposites were characterized by X-ray diffraction, Raman spectroscopy, thermogravimetric analysis-mass spectroscopy, scanning electronic microscopy, transmission electronic microscopy, X-ray photoelectron spectroscopy and gas sorption. It is found that CoS nanoparticles homogenously dispersed in the in situ formed N, S co-doped porous carbon/graphene matrix. The CoS@C/10Graphene composite not only shows excellent electrocatalytic activity toward ORR with high onset potential of 0.89 V, four-electron pathway and superior durability of maintaining 98% of current after continuously running for around 5 h, but also exhibits good performance for OER and HER, due to the improved electrical conductivity, increased catalytic active sites and connectivity between the electrocatalytic active CoS and the carbon matrix. This work offers a new approach for the development of novel multifunctional nanocomposites for the next generation of energy conversion and storage applications.     

电催化氮气还原合成氨反应中抑制水解析氢竞争的研究进展

传统工业合成氨Haber-Bosch工艺条件要求严苛,并且存在高能耗以及高CO₂排放问题。电催化氮气还原（nitrogen reduction reaction, NRR）是一种在常温常压下利用氮气合成氨的新工艺,具有成本低、反应条件温和、环境友好等优势。但该反应所需过电位较高,水解析氢反应（hydrogen evolution reaction, HER）竞争明显,导致电流密度和选择性较低,无法达到工业应用水平。本文在介绍电催化NRR合成氨的反应机理的基础上,主要从氮气分子的吸附活化和电还原阶段反应过程出发,综述了电催化氮气还原合成氨反应中HER与NRR的竞争机制。重点梳理了通过设计催化剂和反应体系抑制HER的国内外最新研究成果,最后对电催化NRR合成氨面临的挑战和机遇进行了展望。     

氢氧直接合成过氧化氢用钯基催化剂研究进展

开发高活性、高选择性的催化剂是实现氢氧直接合成过氧化氢（DSHP）工业化应用的关键。本文系统性地综述了Pd基DSHP催化剂的设计、制备与开发,从催化作用机理、活性组分优化、形貌与尺寸调控、载体选择、制备方法改进、反应添加剂选择、反应环境调节等角度,着重讨论了目前对Pd基催化剂的活性和选择性的优化策略。最后对DSHP用Pd基催化剂的研究进展进行了总结,并对其未来发展前景进行了展望。     

Green Synthesis of M0 Nanoparticles (M=Pd,Pt, and Ru) for Electrocatalytic Hydrogen Evolution

In recent years the demand for green synthesis and green energy has increased immensely. Herein M⁰ nanoparticles were synthesized using a metal precursor and NaHCO₃ under hydrothermal conditions without using any reducing agent. The nanoparticles were characterized using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). Surprisingly, it found that the Pt and Pd nanoparticles contain a high concentration of carbon. The presence of carbon is also evident from the attenuated transmission resonance infra-red (ATRIR) spectroscopy. Moreover, acetic acid was detected as a byproduct of the hydrothermal reaction. NaHCO₃ can be considered as the dissolution of CO₂ in a mildly alkaline solution. Thus, during the reaction, CO₂ was converted to carbonaceous material, which can be considered as a fixation of CO₂. The synthesized nanoparticles are also efficient catalysts for the electrocatalytic hydrogen evolution reaction (HER). It was found that Ru nanoparticles exhibit the highest activity among the three catalysts studied.     

A dual metal-organic framework strategy for synthesis of FeCo@NC bifunctional oxygen catalysts for clean energy application

Developing high efficient bifunctional oxygen electrocatalysts for clean energy applications like Zin-air battery (ZAB) is highly desired, because it would reduce the cost and speed up the practical application of ZAB. Here we use a dual metal–organic framework (MOF) synthesis strategy to prepare the N-doped carbon supported bimetallic FeCo nanoparticle catalysts (marked as FeCo@NC) by pyrolysis of ZnCo-ZIF/MIL-101(Fe) composite. The FeCo@NC exhibits remarkable electrocatalytic activity for ORR with half-wave potential of 0.89 V vs. the reversible hydrogen electrode (RHE) and robust durability for both ORR and OER (oxygen reduction reaction and oxygen evolution reaction), which is attributed to the generation of Fe_0.26Co_0.74 crystalline phase and mesopores due to the dual-MOF synthesis strategy. The rechargeable ZAB based on FeCo@NC air electrode shows a maximum energy density of 139.6mW·cm^-2 and excellent cyclic stability over 130 h, significantly surpassing the Pt and Ir-based ZAB. The present work provides a useful dual-MOF synthesis strategy for preparing high-performance multifunctional catalysts for ORR, OER and hydrogen evolution reaction (HER).     

碱性电解水析氢中的异质结构催化剂

碱性环境下单相金属催化剂的电催化产氢的动力学过程普遍缓慢远不及其在酸性条件，且存在易腐蚀等问题。近期很多异质结构催化剂被报导在碱性条件下表现出优异的析氢性能或长时间的耐用性，其中一些非贵金属催化剂达到了与贵金属基催化剂类似的高催化活性，为碱性条件下产氢催化剂的设计与开发提供了新思路。首先，介绍了异质结构相较于单一材料在产氢催化中的优势，并补充说明了碱性产氢理论相关背景。然后，追溯异质结构在碱性产氢催化剂中的研究路径，主要介绍了异质结构催化剂中极其重要且报导众多的过渡金属氢氧化物基、氧化物基以及硫化物基的异质结构催化剂，通过实例展示异质结构催化剂的制备方法、表征策略以及相应的设计思路。最后，分析了异质结构催化剂在固有活性比较中的困难并对异质结构催化机理的未来研究进行了展望。     

Co-Doped MoSe2 Nanoflowers as Efficient Catalysts for Electrochemical Hydrogen Evolution Reaction (HER) in Acidic and Alkaline Media

Transition metal dichalcogenides (TMDCs) based materials are considered as highly active alternatives to the precious Pt-based catalysts for the hydrogen evolution reaction (HER). In particular, MoSe₂ emerges as a promising catalyst due to its abundance and electrochemical stability, but further modifications are still required to enhance its performance, specifically in alkaline conditions. Here, we developed a method to obtain MoSe₂ with two cobalt doping patterns: homogeneously doped and edge doped nanoflowers, with abundant edge sites and extended surface area. The results show that low concentration of doping enhances the catalytic activity toward HER. Incorporation of cobalt as a substituent dopant within the layered structure of MoSe₂ appears to have two major contributions: it changes the chemical environment providing more active sites with favored hydrogen adsorption properties, and improves the charge transfer resistance and thus facilitates the HER kinetics. Moreover, the homogeneous and edge-doped nanoflowers show different pH-dependence of HER activity. Edge-doped samples exhibit significantly improved performance in acidic medium, while the overpotential increases in alkaline environment upon doping. A mechanistic explanation of the observed effect is proposed. This work opens up an additional path for improving the catalytic activity of TMDCs in acidic or alkaline medium using a simple and facile method with only small quantities of dopants.