碳纳米纤维负载铁钴镍硼化物可控制备及其电催化析氢性能研究

通过乙醇催化燃烧法制备了碳纳米纤维（CNFs），采用化学沉积法在CNFs载体上负载铁钴镍硼化物（FeCoNiB），并以多种测试手段对其表征，研究了化学沉积工艺条件对FeCoNiB粒径、分散、成分及结构的影响，建立了碳纳米纤维负载的铁钴镍硼化物（FeCoNiB/CNFs）可控制备方法。采用电化学测试手段研究了FeCoNiB/CNFs在碱性环境下的氢气析出反应（HER）催化性能。结果表明，在100 mA/cm²的电流密度下，FeCoNiB/CNFs的过电位仅为366 mV，塔菲尔斜率低至41 mV/dec；在持续10 h的稳定性测试中电位衰减幅度很小，基本保持不变。这说明FeCoNiB/CNFs制备成本低，但其高稳定性可媲美贵金属的高催化活性HER催化剂；该研究可为非贵金属HER催化剂的研制及低成本电解水制氢技术的规模化应用提供参考。     

焦耳热快速合成双功能电催化剂用于高效水分解

电解水是有效的产氢方式之一, 开发具有高催化活性的电极材料是当前电解水的研究热点,但仍面临诸多挑战。 本研究报告了一种通过焦耳热技术快速制备多金属异质结构, 并将其用作电解水的双功能电催化剂, 展现出优异的电解水催化活性。通过焦耳热处理三种金属前驱涂覆的碳布, Mo₂C和CoO/Fe₃O₄异质结构形成。当其用作析氢（HER）和析氧（OER）的双功能催化剂时, 仅需121 mV和268 mV的过电位,可以实现10 mA·cm^-2的电流密度。当用于两电极电解水时, MoC/FeO/CoO/CC作为阳极和阴极催化剂表现出优异的电催化性能和长期稳定性, 仅需1.69 V即可实现10 mA·cm^-2的电流密度, 并且展现出25小时的稳定性。本研究通过简单、 快速的焦耳热技术实现了双金属/多金属异质结构的构筑,并应用于高效水电解,为合理设计多金属异质结构提供指导。     

纳米非晶镍硼合金的合成及其碱性电催化析氢性能研究（英文）

可持续能源电解水制氢是实现零碳排放氢经济的有效途径。碱性环境下的电催化析氢反应(HER)是电解水技术主要的能量转换过程之一。开发高活性、低成本的非贵金属催化剂是碱性电解水析氢反应的关键所在。本研究以壳寡糖为保护剂,采用简单易行的化学还原法制备了纳米NiB非晶合金电催化剂并用于碱性析氢反应。采用X射线衍射(XRD)、透射电子显微镜(TEM)、电感耦合等离子体分析(ICP)和X射线光电子能谱(XPS)等多种表征方法研究了不同条件下获得的催化剂结构组成及特征物性参数。结果表明,壳寡糖的加入可以有效调控纳米粒子的平均粒径为4 nm左右,提升活性比表面积,增加活性位点,从而提高其电催化活性。所制备的NiB-COS在1.0 mol/L NaOH中表现出优异的HER性能,析氢反应起始过电位仅为15.1 mV,在电流密度为10 mA/cm²时HER过电位为49.4 mV,Tafel斜率为86.1 mV/dec,为制备高活性、低成本、简单易得的HER电催化剂提供了重要策略。     

电解海水析氢反应过渡金属基催化剂的研究进展

海水作为地球上最丰富的自然资源之一,在实现大规模的电解水制氢方面具有得天独厚的优势。然而,海水中的Cl^-、Ca²⁺和Mg²⁺等使催化剂在阴极发生腐蚀、毒化或降解,导致其稳定性、活性以及使用寿命显著降低。近年来,为了解决上述问题,人们致力于设计开发廉价的高效稳定析氢反应（HER）催化剂,进而提高电解海水制氢效率。本文首先介绍了电解海水的优势及其HER所面临的挑战,其次从活性和稳定性等方面重点论述了硒化物、硫化物、氮化物以及磷化物等过渡金属基催化剂在电解海水HER中的研究进展,最后总结和展望了电解海水HER催化剂未来的发展前景。     

氧空位和磷掺杂协同增强铁钴基材料电解水催化性能

为了研发高效、稳定的电解水催化剂,我们以氧空位和磷掺杂为基础,通过原位浸泡生长和两步热处理的方法,在泡沫铁上合成具有氧空位和磷掺杂的纳米花结构作为析氢反应(HER)和析氧反应(OER)双功能电催化剂。CoFe₂O₄已被报道为一种很有前途的OER和氧还原反应(ORR)电催化剂,然而CoFe₂O₄在HER中表现出电导率差、电催化反应慢的特性。CoFe₂O₄中氧空位(Ov)的形成可以有效调控催化剂表面的电子结构,有助于产生更多的缺陷和空位,从而提高OER的活性。随后,引入磷原子填充在空位中,制备的P-Ov-CoFe₂O₄/IF在碱性电催化测试中展现出优异的HER和OER性能,在10 mA·cm^-2电流密度下HER和OER过电位仅为54和191 mV,Tafel斜率分别为57和54 mV·dec^-1,并具有良好的循环稳定性。     

碱性电解水高效制氢

与传统化石能源制氢技术相比,利用可再生能源驱动电解水制氢技术具有绿色可持续和制氢效率高等优势,被认为是目前最具前景的制氢方式。然而, 由于电解水两极反应动力学缓慢、 催化剂稳定性较差, 限制了其大规模发展。此外, 阳极析氧反应存在较高的过电势, 从而导致当前制氢能耗与成本较高, 严重制约了其商业化应用。 为了解决上述问题与挑战,本文对当前发展较为成熟的碱性电解水技术进行了综合讨论与分析。 首先, 对电解水发展历程中的重要节点进行了总结, 便于读者了解该领域。进一步, 从电催化剂、 电极、 反应和系统的角度深入总结了提升电解水制氢性能的有效策略。作者分别介绍了近年来层状双金属氢氧化物基电解水催化剂、电解水制氢耦合氧化反应以及可再生能源驱动的电解水系统的重要研究进展; 同时对结构化催化剂在电解水应用中的构效关系进行了深入分析。最后, 对该领域存在的挑战和未来发展方向进行了展望,希望能为氢能的发展和推广提供一定的思路。     

MoP-NC纳米球负载Pt纳米粒子用于高效甲醇电解

实现绿色甲醇电解制氢需要高效的双功能催化剂。本文采用热处理结合乙二醇还原法成功制备了MoP-NC纳米球负载的超细Pt纳米粒子(平均粒径为2.53 nm)复合催化剂(Pt/MoP-NC)用于高效甲醇电解制氢。MoP-NC纳米球不仅能提高Pt纳米粒子的分散性并且增强Pt的抗中毒能力。电化学测试表明Pt/MoP-NC催化剂在酸性甲醇氧化反应(MOR)和析氢反应(HER)中具有较高的催化性能;其中,MOR的正向扫描峰值电流密度为90.7 mA∙cm⁻²,是商业Pt/C催化剂的3.2倍,在10 mA∙cm⁻²的电流密度下,HER的过电位低至30 mV,与商业Pt/C接近。由Pt/MoP-NC||Pt/MoP-NC组装的两电极电解槽驱动10 mA∙cm⁻²的电流密度仅需要0.67 V的电压,比相同条件下电解水的电压低1.02 V,大大降低了能量输入。Pt/MoP-NC的高催化性能主要来源于Pt活性中心与相邻层状多孔球形结构的MoP-NC载体之间电子效应及配体效应引起的抗一氧化碳中毒能力的提升和含氧物种的容易生成。     

双金属氮化物NiMoN析氢催化剂制备及其电解海水析氢性能的研究

电解水制氢是最具潜力的绿氢制备技术, 而高效析氢反应(HER)催化剂的开发对其大规模推广意义重大. 选用氯化镍和钼酸铵为镍源和钼源, 通过原位生长法获得NiMo双金属催化剂前驱体, 再以二腈二胺为氮源, 高温氮化-程序升温法制备了一系列NiMo_xN@NC催化剂(x代表钼酸铵和氯化镍的物质的量比), 并对催化剂进行了结构、形貌以及金属价态表征. 分别在1 mol/L KOH碱液以及模拟海水中分析了析氢(HER)性能. 结果表明, 碱液中NiMo_xN@NC催化剂均具有良好的电荷转移速率(R_ct<1 Ω), 具有较好的内在催化活性(Tafel斜率103~168 mV/dec). 其中, NiMo_0.75N@NC催化剂具有最高的极限电流(–178 mA/cm²), 最小的过电势η₁₀=0.164 V, η₁₀₀=0.448 V), 最高的内在催化活性, Tafel斜率只有103 mV/dec, 且具有较好的稳定性. 在海水中, 在10 mA/cm²和40 mA/cm²的负载电流下, NiMo_0.75N@NC催化剂依旧表现出了较好的稳定性.     

多壳层中空镍钴双金属磷化物纳米球用于高效电催化析氧北大核心CSCD

析氧反应是金属-空气电池和电解水制氢等电化学系统中关键的反应,研究其高效稳定非贵金属电催化剂至关重要。本文以金属有机骨架化合物(MOF)作为前驱体,通过高温煅烧制备了具有多壳层中空结构的镍钴双金属磷化物(NiCo-P)。这种独特的结构有利于电解液的渗透,能够提供丰富的暴露活性位点和快速传质路径,同时,镍钴双金属具有协同作用促进电化学性能。结果表明,n(Ni)∶n(Co)=1∶10制备的NiCo-P-0.1催化剂在1.0 mol/L KOH电解液中表现出良好的催化活性和稳定性,在10 mA/cm^(2)电流密度的过电势为329 mV,具有良好的应用前景。本工作为高活性和高稳定性的电催化析氧催化剂的制备提供了一种全新途径。     

负载于三维镍网上的磷化钴纳米珠链阵列的高效水电解性能研究

研究廉价且高效的水分解电催化剂对于氢能源的开发利用具有重要意义,过渡金属磷化物是最有前景的水分解双功能电催化剂之一。本研究采用先水热法,再低温磷化的简单的两步合成法,在三维镍网上生长CoP纳米珠链阵列,所生成的镍网(Nickel foam,NF)负载CoP纳米珠线阵列(CoP/NF),具有规则的形貌、较大的比表面积,在碱性条件下对氢气析出反应(HER)和氧气析出反应(OER)都表现出良好的电催化性能。在电流密度达到10 mA/cm~2时的过电位分别为280 mV(OER)及95 mV(HER)。利用此CoP/NF复合材料组成的双电极体系可以有效电解水,在电流密度为10 mA/cm~2时所需的施加电压仅为1.63 V,并且表现出非常高的稳定性。     

A General Route to Prepare Low-Ruthenium-Content Bimetallic Electrocatalysts for pH-Universal Hydrogen Evolution Reaction by Using Carbon Quantum Dots

A challenging but pressing task to design and synthesize novel, efficient, and robust pH-universal hydrogen evolution reaction (HER) electrocatalysts for scalable and sustainable hydrogen production through electrochemical water splitting. Herein, we report a facile method to prepare an efficient and robust Ru-M (M=Ni, Mn, Cu) bimetal nanoparticle and carbon quantum dot hybrid (RuM/CQDs) for pH-universal HER. The RuNi/CQDs catalysts exhibit outstanding HER performance at all pH levels. The unexpected low overpotentials of 13, 58, and 18 mV shown by RuNi/CQDs allow a current density of 10 mA cm⁻² in 1 m KOH, 0.5 m H₂SO₄, and 1 m PBS, respectively, for Ru loading at 5.93 μgRu cm⁻². This performance is among the best catalytic activities reported for any platinum-free electrocatalyst. Theoretical studies reveal that Ni doping results in a moderate weakening of the hydrogen bonding energy of nearby surface Ru atoms, which plays a critical role in improving the HER activity.     

A General Route to Prepare Low‐Ruthenium‐Content Bimetallic Electrocatalysts for pH‐Universal Hydrogen Evolution Reaction by Using Carbon Quantum Dots

A challenging but pressing task to design and synthesize novel, efficient, and robust pH‐universal hydrogen evolution reaction (HER) electrocatalysts for scalable and sustainable hydrogen production through electrochemical water splitting. Herein, we report a facile method to prepare an efficient and robust Ru‐M (M=Ni, Mn, Cu) bimetal nanoparticle and carbon quantum dot hybrid (RuM/CQDs) for pH‐universal HER. The RuNi/CQDs catalysts exhibit outstanding HER performance at all pH levels. The unexpected low overpotentials of 13, 58, and 18 mV shown by RuNi/CQDs allow a current density of 10 mA cm^?2 in 1 m KOH, 0.5 m H₂SO₄, and 1 m PBS, respectively, for Ru loading at 5.93 μgRu cm^?2. This performance is among the best catalytic activities reported for any platinum‐free electrocatalyst. Theoretical studies reveal that Ni doping results in a moderate weakening of the hydrogen bonding energy of nearby surface Ru atoms, which plays a critical role in improving the HER activity.     

Bimetallic Ru-Ni/TiO_2 catalysts for hydrogenation of N-ethylcarbazole:Role of TiO_2 crystal structure

Hydrogenation of N-ethylcarbazole(NEC), the hydrogen lean form of a liquid organic hydrogen carrier,on TiO_2 supported Ru-Ni bimetallic catalysts is investigated. Crystal structure of TiO_2 plays a critical role on the hydrogenation activity and selectivity towards fully hydrogenated product. Ru/anatase catalyst exhibits higher selectivity but lower reactivity compared to Ru/rutile catalyst. Ni addition significantly promotes the performance of Ru/anatase catalyst while causes severe performance deterioration of Ru/rutile catalyst. Commercial P25, a mixture of anatase and rutile phases in approximate ratio A/R~1/4,is found to be the best TiO_2 support for NEC hydrogenation. Ru/P25 catalyst outperforms both Ru/rutile and Ru/anatase and its activity can be further slightly improved by Ni addition. The unexpected synergism between the two different TiO_2 phases for Ru based NEC hydrogenation catalysts is related to metal-support interaction and Ru-Ni interaction.     

非晶非贵金属催化剂的研究进展及展望

近年来电解水产氢作为一种具有前景的制备及储存可再生能源的方法受到了各界的广泛关注.在此过程中,电解水催化剂是提高能源转换效率的关键.优秀的催化剂应具备高催化活性、高稳定性、低成本以及可大规模生产等性质.科研工作者对电解水的两部分反应,即析氢反应以及析氧反应均进行了广泛及深入的研究.目前,贵金属催化剂,如铂基、钌基催化剂的催化活性要高于其他元素催化剂,但由于其价格昂贵,储量较少使得贵金属催化剂无法得到大规模应用,因此发展非贵金属催化剂对绿色能源的发展具有重要意义.一般而言,催化剂的结晶度越高,其催化活性越好,而近年来非晶催化剂以其更高的催化活性位密度也越来越受到人们的重视.同时,非晶催化剂的成分更加灵活,相比晶体催化剂来说非晶催化剂可以在更大范围内对成分进行调节.此外,非晶催化剂的制备通常都在较为温和的反应条件下进行,这也能够降低生成成本,促进其工业化发展.在这篇综述里我们介绍了电解水反应的基本原理,总结了近期非晶析氢、析氧以及双功能催化剂的研究进展.并随后探讨了电解水反应目前的难点并对非晶催化剂的制备进行了展望.     

Hollow Chevrel‐Phase NiMo3S4 for Hydrogen Evolution in Alkaline Electrolytes

Electrochemical water splitting to generate molecular hydrogen requires catalysts that are cheap, active, and stable, particularly for alkaline electrolyzers, where the cathodic hydrogen evolution reaction is slower in base than in acid even on platinum. Herein, we describe the synthesis of new hollow Chevrel‐phase NiMo₃S₄ and its alkaline hydrogen evolution reaction (HER) performance: onset potential of ?59 mV, Tafel slope of 98 mV per decade, and exchange current density of 3.9×10^?2 mA cm^?2. This Chevrel‐phase chalcogenide also demonstrates outstanding long‐term stability under harsh HER cycling conditions. Chevrel‐phase nanomaterials show promise as efficient, low‐cost catalysts for alkaline electrolyzers.     

Electron-transfer enhanced MoO2-Ni heterostructures as a highly efficient pH-universal catalyst for hydrogen evolution

Hydrogen is one of the most promising energy carriers to replace fossil fuels and electrolyzing water to produce hydrogen is a very effective method. However, designing highly active and stable non-precious metal hydrogen evolution electrocatalysts that can be used in universal pH is a huge challenge. Here, we have reported a simple strategy to develop a highly active and durable non-precious MoO_2-Ni electrocatalyst for hydrogen evolution reaction(HER) in a wide pH range. The MoO_2-Ni catalyst exhibits a superior electrocatalytic performance with low overpotentials of 46, 69, and 84 mV to reach-10 mA cm~(-2) in 1.0 M KOH, 0.5 M H_2SO_4,and 1.0 M PBS electrolytes, respectively. At the same time, the catalyst also shows outstanding stability over a wide pH range. It is particularly noted that the catalytic performance of MoO_2-Ni in alkaline solution is comparable to the highest performing catalysts reported. The outstanding HER performance is mainly attributed to the collective effect of the rational morphological design, electronic structure engineering, and strong interfacial coupling between MoO_2 and Ni in heterojunctions.This work provides a viable method for the synthesis of inexpensive and efficient HER electrocatalysts for the use in wide pH ranges.     

Ru Nanoparticles Supported on Co-Embedded N-Doped Carbon Nanotubes as Efficient Electrocatalysts for Hydrogen Evolution in Basic Media

A challenging but urgent task is to construct efficient and robust hydrogen evolution reaction(HER) electrocatalysts for practically feasible and sustainable hydrogen production through alkaline water electrolysis. Herein we report a simple and mild pyrolysis method to synthesize the efficient Ru nanoparticles(NPs) supported on Co-embedded N-doped carbon nanotubes(Ru/Co-NCNTs) catalyst for HER in basic media. The Ru/Co-NCNTs display remarkable performance with a low overpotential of only 35 mV at 10 mA/cm², a small Tafel slope(36 mV/dec), and a high mass activity in 1 mol/L KOH, which is superior to commercial 20% Pt/C catalyst. This excellent performance is benefited from the enhanced conductivity of N-doped carbon nanotubes(NCNTs) and high intrinsic activity triggered by synergistic coupling between Ru NPs and Co-embedded N-doped carbon nanotubes(Co-NCNTs).     

Potential‐Cycling Synthesis of Single Platinum Atoms for Efficient Hydrogen Evolution in Neutral Media

Single‐atom catalysts (SACs) have exhibited high activities for the hydrogen evolution reaction (HER) electrocatalysis in acidic or alkaline media, when they are used with binders on cathodes. However, to date, no SACs have been reported for the HER electrocatalysis in neutral media. We demonstrate a potential‐cycling method to synthesize a catalyst comprising single Pt atoms on CoP‐based nanotube arrays supported by a Ni foam, termed PtSA‐NT‐NF. This binder‐free catalyst is centimeter‐scale and scalable. It is directly used as HER cathodes, whose performances at low and high current densities in phosphate buffer solutions (pH 7.2) are comparable to and better than, respectively, those of commercial Pt/C. The Pt mass activity of PtSA‐NT‐NF is 4 times of that of Pt/C, and its electrocatalytic stability is also better than that of Pt/C. This work provides a large‐scale production strategy for binder‐free Pt SAC electrodes for efficient HER in neutral media.     

An Efficient RuTe2/Graphene Catalyst for Electrochemical Hydrogen Evolution Reaction in Acid Electrolyte

Developing efficient powder catalysts for hydrogen evolution reaction (HER) in the acidic electrolyte is significant for hydrogen generation in the proton exchange membrane (PEM) water electrolysis technique. Herein, we demonstrated an efficient catalyst for HER in the acid media based on the graphene supported ruthenium telluride nanoparticles (RuTe₂/Gr). The catalysts were easily fabricated by a facile microwave irradiation/thermal annealing approach, and orthorhombic RuTe₂ crystals were found anchored over the graphene surface. The defective structure was demonstrated in the aberration‐corrected transmission electron microscopy images for RuTe₂ crystals and graphene support. This catalyst required an overpotential of 72 mV to drive 10 mA cm^?2 for HER when loading on the inert glass carbon electrode; Excellent catalytic stability in acidic media was also observed to offer 10 mA cm^?2 for 10 hours. The Volmer‐Tafel mechanism was indicated on RuTe₂/Gr catalyst by Tafel slope of 33 mV dec^?1, similar to that of Pt/C catalysts. The high catalytic performance of RuTe₂/Gr could be attributed to its high dispersion on the graphene surface, high electrical conductivity and low charge transfer resistance. This powder catalyst has potential application in the PEM water electrolysis technique because of its low cost and high stability.