自支撑型过渡金属磷化物电催化析氢反应研究

氢能作为一种零碳排放的清洁能源,主要通过电解水的途径获得。电解水析氢过程所使用的贵金属Pt基催化剂非常稀缺和昂贵,因此开发具有高活性和稳定性的非贵金属催化剂仍然是一个巨大的挑战。自支撑型过渡金属磷化物析氢性能优异,加之有效结合了自支撑基底的诸多优势,有望成为可替代贵金属Pt基催化剂的优良析氢材料。本文详细介绍了自支撑型过渡金属磷化物的研究进展,着重论述了此类型电催化剂的析氢优势及作用机理：（1）自支撑基底3D集成框架导电性较强,可提供大量的电子转移通道,从而加速催化反应进程;（2）自支撑型过渡金属磷化物较大的比表面积将会暴露出更多的活性位点,进而促进催化反应的发生;（3）自支撑型过渡金属磷化物可以直接作为阴极进行析氢反应,避免传统涂覆法中催化剂容易从玻碳电极脱落的弊端。最后,总结了此类型电催化剂用于电解水反应所面临的问题和挑战,并进行了合理的展望。     

基于碳纤维材料基底的电解水制氢催化剂的研究进展

电解水制氢技术是未来获得清洁氢能源的有效途径之一。铂作为高效的电解水制氢催化剂,由于其价格昂贵,难以回收,不利于氢能源与氢经济的发展,因此发展高效的非贵金属电催化剂,使电解水制氢过程更加高效、经济化是十分关键的科学问题。本文综述了近年来电解水制氢催化剂的研究进展,重点集中在以碳纤维材料为基底的非贵金属催化剂领域。总结了几类重要的多相异质非贵金属催化剂,包括磷化物、硫化物、硒化物、碳化物、氧化物催化剂等,重点探讨了各种析氢催化剂的合成方法和性能提高策略。同时,本文也简要概述了碳纤维基底材料在电分析化学检测方面的应用研究。     

非贵金属析氢电催化剂的结构调控研究进展

能源危机和环境污染日益严重,寻找可持续且清洁的新能源成为趋势,而氢能被视为最理想的选择。贵金属基催化剂虽活性优异但成本高、稳定性差,因此开发可代替如铱（Ir）和钌（Ru）等贵金属催化剂的非贵金属催化剂是研究热点,而掌握析氢反应（Hydrogen Evolution Reaction,HER）机理是合成新型高效电催化剂的关键。本文综述了近年来非贵金属基HER催化剂的研究进展,围绕Fe、Co、Ni和Mn等非贵金属对电催化构建策略和提高催化活性进行了讨论,其中包括组分调控和缺陷工程等方面。此外,还展望了HER催化剂的应用前景。     

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。     

二硫化钼析氢电催化剂

电解水与一次可再生能源耦合,可同时提供洁净制氢方式与先进的能源转化技术,有望在未来清洁能源经济中扮演重要角色,而实现这一美好愿景的关键在于研发高活性、低成本的析氢/析氧电催化材料。二硫化钼(MoS₂)是颇具代表性的非贵金属析氢电催化材料,纵观其研究历程,先导性理论预测与材料设计、先进制备与表征技术的应用均在改性研究中发挥了至关重要的作用,这也从一个侧面折射出当代电催化剂的研究模式与发展趋势。本文按照重要发现与进展的时间顺序,梳理了MoS₂析氢电催化剂的发展历程,重点论述了增多边缘活性位、提高导电性、构筑基面活性位等改性策略的实施方法、效果与机理,最后从全领域总结了MoS₂析氢电催化剂的研究启示并展望其未来发展趋势。     

Au-Pt催化剂的控制合成及其对乙醇电氧化性能

乙醇电氧化（EOR）是直接乙醇燃料电池和电解乙醇制氢共有的阳极反应.Au@Pt核壳和AuPt合金是广泛使用的两种电催化材料,迄今尚无两者对EOR性能的对比研究.以CO作为还原剂和淬灭剂合成了近似Pt单层的Au@Pt/C催化剂,作为对照,以NaBH₄还原法合成了相同Au∶Pt物质的量比和金属载量的AuPt/C催化剂;运用透射电子显微镜（TEM）、扫描透射电子显微镜-能谱仪（STEM-EDS）、X射线粉末衍射（XRD）和X射线光电子能谱（XPS）等手段综合表征了两者结构之差异,同时以电化学循环伏安法和计时电流法测试了在碱性体系中其对EOR的电催化性能.结果表明,相比于商业化的Pt/C和Au/C,Au@Pt/C和AuPt/C对EOR的活性和稳定性均有着显著提升;Au@Pt/C对EOR的电催化活性和对C-C键断裂能力略优于AuPt/C.双金属催化剂中Au与Pt之间的晶格应力和部分电荷转移等效应可能是其性能提升的主要原因.     

C_3N_4-Ti_4O_7-MoS_2复合催化剂界面效应增强电催化析氢性能（英文）

电催化水裂解是目前最有前景的制氢技术之一。二硫化钼(MoS_2)作为最有前途的非贵金属电解水制氢催化剂之一,受有限的催化位点和弱电导率的困扰,迫切地需要被进一步优化。本文采用简单的水热方法构建了C_3N_4-Ti_4O_7-MoS_2异质催化剂,利用活性组分间的界面相互作用,实现了催化剂活性位点的高度暴露、表面电荷的再分布、氢吸附动力学和稳定性的优化,改进了MoS2的电催化析氢性能。结果表明,界面效应赋予C_3N_4-Ti_4O_7-MoS_2催化剂优异的电催化活性,即300 mV的过电位下获得50 mA/cm~2的电流密度以及较低的Tafel斜率(54 mV/dec),长达33 h的析氢反应后仍保持高的催化活性,其电催化析氢性能优于纯MoS_2。结果表明,界面效应作为一种合理改进MoS_2基电催化剂的策略,对开发新型高效制氢电催化剂的发展至关重要。     

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.     

纳米二硫化钼的掺杂及催化电解水产氢的研究进展

电催化水分解制氢是可以形成闭环的生产过程, 起始原料与副产物均为水、 过程清洁无污染, 是极具希望的产氢策略. 目前制约其发展的瓶颈之一是价格昂贵的Pt基贵金属催化剂. 为推动电催化分解水制氢的普及, 亟待开发低成本非贵金属催化剂. 在众多备选非贵金属催化材料中, 纳米层状结构二硫化钼(MoS₂)因催化效果可期、 价格低而获得了广泛关注. 然而, 通常条件下易于获得的层状结构2H相MoS₂大面积的基面部分显示惰性, 仅在片层边缘处存在少量活性位点, 且导电性较差, 因而尚不能替代Pt基催化剂, 而如何增加其活性位点数量和提高其导电性成为亟待解决的问题; 另一方面, 1T相MoS₂虽然活性高、 导电性好, 但却存在制备困难及稳定性差的问题. 鉴于此, 研究者通过对纳米MoS₂进行掺杂改性实现了其活性与稳定性的有效提升. 本文对非贵金属纳米MoS₂催化剂掺杂改性的方法、 机理及其电催化水解制氢性能的相关研究进行了总结与讨论. 作为典型的非贵金属电解水析氢催化剂, MoS₂具有巨大发展潜力, 本文能够对相关非贵金属催化剂的研发提供有益的参考.     

非贵金属电催化析氧催化剂的最新进展

氢气具有环境友好、含量丰富、高能量密度等特点,是一种可以替代化石能源的绿色环保可再生能源. 电解水是制备氢气最有效途径之一. 但在电解水过程中,动力学过程非常缓慢,过电位较大的阳极析氧半反应严重限制了阴极析氢反应效率. 因此,研究高效、稳定和低成本的催化剂来降低析氧反应的过电位,从而提高析氢反应效率受到了广泛关注. 基于非贵金属催化剂本身特性及其在高浓度OH-条件下具有较高OER催化活性等原因,本文首先简要介绍碱性条件下析氧反应机理及其性能的评价方法,然后重点讨论非贵金属电催化析氧催化剂的最新研究进展. 最后对如何深入研究催化机理、设计高效、双功能及新型非贵金属电催化析氧催化剂进行了展望.     

Multifunctional Active-Center-Transferable Platinum/Lithium Cobalt Oxide Heterostructured Electrocatalysts towards Superior Water Splitting

Designing cost-effective and efficient electrocatalysts plays a pivotal role in advancing the development of electrochemical water splitting for hydrogen generation. Herein, multifunctional active-center-transferable heterostructured electrocatalysts, platinum/lithium cobalt oxide (Pt/LiCoO₂) composites with Pt nanoparticles (Pt NPs) anchored on LiCoO₂ nanosheets, are designed towards highly efficient water splitting. In this electrocatalyst system, the active center can be alternatively switched between Pt species and LiCoO₂ for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Specifically, Pt species are the active centers and LiCoO₂ acts as the co-catalyst for HER, whereas the active center transfers to LiCoO₂ and Pt turns into the co-catalyst for OER. The unique architecture of Pt/LiCoO₂ heterostructure provides abundant interfaces with favorable electronic structure and coordination environment towards optimal adsorption behavior of reaction intermediates. The 30 % Pt/LiCoO₂ heterostructured electrocatalyst delivers low overpotentials of 61 and 285 mV to achieve 10 mA cm⁻² for HER and OER in alkaline medium, respectively.     

Multifunctional Active‐Center‐Transferable Platinum/Lithium Cobalt Oxide Heterostructured Electrocatalysts towards Superior Water Splitting

Designing cost‐effective and efficient electrocatalysts plays a pivotal role in advancing the development of electrochemical water splitting for hydrogen generation. Herein, multifunctional active‐center‐transferable heterostructured electrocatalysts, platinum/lithium cobalt oxide (Pt/LiCoO₂) composites with Pt nanoparticles (Pt NPs) anchored on LiCoO₂ nanosheets, are designed towards highly efficient water splitting. In this electrocatalyst system, the active center can be alternatively switched between Pt species and LiCoO₂ for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Specifically, Pt species are the active centers and LiCoO₂ acts as the co‐catalyst for HER, whereas the active center transfers to LiCoO₂ and Pt turns into the co‐catalyst for OER. The unique architecture of Pt/LiCoO₂ heterostructure provides abundant interfaces with favorable electronic structure and coordination environment towards optimal adsorption behavior of reaction intermediates. The 30 % Pt/LiCoO₂ heterostructured electrocatalyst delivers low overpotentials of 61 and 285 mV to achieve 10 mA cm^?2 for HER and OER in alkaline medium, respectively.     

负载无定型钌纳米簇的原子级钴掺杂一维碳纳米笼增强析氢催化性能

析氢反应是电解水产制氢的关键反应之一.在碱性条件下,由于催化剂表面与反应过程中产生的氧物种、氢物种与催化剂的吸附未处于最佳状态,析氢反应动力学往往比较缓慢,比在酸性条件下慢2-3个数量级.目前,铂基纳米催化剂被认为是最优的析氢催化剂,但因价格昂贵、稳定性较差,限制了其在电解水器件上的大规模应用.因此,设计一种价格较为低...     

Hollow Heterostructured Nanocatalysts for Boosting Electrocatalytic Water Splitting

The implementation of electrochemical water splitting demands the development and application of electrocatalysts to overcome sluggish reaction kinetics of hydrogen/oxygen evolution reaction (HER/OER). Hollow nanostructures, particularly for hollow heterostructured nanomaterials can provide multiple solutions to accelerate the HER/OER kinetics owing to their advantageous merit. Herein, the recent advances of hollow heterostructured nanocatalysts and their excellent performance for water splitting are systematically summarized. Starting by illustrating the intrinsically advantageous features of hollow heterostructures, achievements in engineering hollow heterostructured electrocatalysts are also highlighted with the focus on structural design, interfacial engineering, composition regulation, and catalytic evaluation. Finally, some perspective insights and future challenges of hollow heterostructured nanocatalysts for electrocatalytic water splitting are also discussed.     

由长链醇选择性氧化制备香料(英文)

The activity and the selectivity of Ru and Pt based carbon catalysts in the selective oxidation of long-chain aliphatic alcohols (C8, C10, C12) have been investigated. Ru/AC and Pt/AC always showed good initial activity, however deactivation phenomena rapidly depressed the catalytic per-formance of the catalysts. These phenomena can be limited by modification of Ru/AC and Pt/AC with Au improving the durability of the catalyst. Ru/AC and AuRu/AC showed good selectivity to the corresponding aldehyde (95%) making these catalysts promising for fragrances manufacturing. The advantage in using Au modified catalyst lies on the easier regeneration procedure com-pared to the one necessary for Ru/AC. Pt /AC and AuPt/AC showed a lower selectivity to aldehyde promoting the formation of the acid and the ester formation respectively. The addition of water in the solvent system speeds up the reaction rate but drastically decreased the selectivity to aldehyde especially in the case of Pt based catalysts.     

利用MOF-253衍生氮掺杂碳限域效应促进Pt纳米单晶电催化剂的氧析出反应

目前,为了有效解决电化学能量转化反应动力学过程缓慢和商业化应用等问题,需要大力提高催化剂的电催化活性和稳定性,并大幅降低贵金属催化剂的用量.通常,铂(Pt)基催化剂对燃料电池的氧还原反应(ORR)和水电解过程的氢析出反应(HER)表现出很高的活性.然而,对于高效的金属-空气电池和水电解装置,其中的氧析出反应(OER)则需要高活性的非Pt电催化剂来降低电化学过电位及提高其对高电位的耐受性.虽然相较于Pt催化剂,IrO2和RuO2等贵金属催化剂表现出了更高的OER活性,然而,它们的稳定性差,难以满足实际应用需求,严重阻碍了其在金属-空气电池和水电解中的应用.通常,Pt对OER的低效催化主要归因于在OER电催化过程中Pt与电解液直接接触,导致Pt表面快速被氧化,形成Pt氧化物(Pt^+4O2和Pt^+2O)层.形成的Pt氧化物对OER不起催化作用,从而降低了Pt的利用率和总的水电解效率.为了避免Pt表面的快速氧化,实现高的OER性能,我们将Pt金属纳米粒子有效地限域在超薄功能多孔碳层内.前期,已有大量的有关金属基ORR和HER催化剂研究证明,这种策略对于稳定金属纳米颗粒非常有效,可有效避免金属催化剂的快速氧化,而且还可抑制金属颗粒迁移和团聚;此外,还有利于增强催化剂的导电性和离子物种的扩散能力,从而提高催化剂的电催化性能.然而,要达到提高金属催化剂OER电催化性能的目的,还需要设计一种具有优良结构的功能化异质原子掺杂多孔碳基限域材料.金属有机框架(MOF),特别是MOF-253,由于具有较高的柔韧性、丰富的孔、可控的几何结构和高比表面积,被认为是制备功能多孔碳基限域材料的理想前驱体.为此,通过结合功能多孔碳基材料的限域作用及MOF-253和超细Pt纳米单晶的优势,本文合成了MOF-253衍生氮掺杂碳(N/C)限域的Pt纳米单晶(Pt@N/C)核壳型电催化剂.制备的Pt-N-C框架不仅具有超薄的氮掺杂活性多孔碳保护层壳体(平均厚度为0.51 nm),还有具高度分散和稳定化的Pt纳米单晶核体;值得指出的是,因受到碳层的限域作用,即使经900℃的高温处理,Pt纳米单晶仍保持了较小的晶体尺寸(平均粒径仅为6.7 nm);此外,该催化剂的Pt载量较低,仅为6.1wt%(Pt@N/C-10).将其作为OER电催化剂,表现出优异的OER性能:在10 mA cm^-2电流密度下,其过电位仅为298 mV,低于商业IrO2催化剂(353 mV);而且,经2000周加速电位扫描后,其电位仅降低19.4 mV,也低于IrO2(23.3 mV).本文很好地证明了通过构建空间限域结构可以有效解决Pt等金属催化剂因表面氧化而导致OER动力学活性和稳定性低的问题.     

Hydrogen evolution reaction on Pt and Ru in alkali with volmer-step promotors and electronic structure modulators

Alkaline water electrolysis despite having a variety of choices for anodic oxygen evolution reaction (OER) catalysts out of non-precious metals suffers significantly due to the poor kinetics of cathodic hydrogen evolution reaction (HER) even with the state-of-the-art Pt and equally active Ru. The Volmer-step (water dissociation (WD) coupled proton adsorption) of alkaline HER is mostly the rate-determining step (RDS) and costs most of the work required. In this review, recent developments in improving the HER kinetics of Pt and Ru with Volmer-step promotors and electronic structure modulators have been comprehensively analyzed and critically presented with the challenges and prospects.     

Engineering morphologies of cobalt oxide/phosphate-carbon nanohybrids for high-efficiency electrochemical water oxidation and reduction

Active non-noble metal catalysts plays a decisive role for water electrolysis,however,the rational design and development of cost-efficient electrocatalysts with Pt/IrO2-like activity is still a challenging task.Herein,a facile one-step electrodeposition route in deep eutectic solvents(DESs) is developed for morphology-controllable synthesis of cobalt oxide/phosphate-carbon nano hybrids on nickel foam(CoPO@C/NF).A series of CoPO@C/NF nanostructures including cubes,octahedrons,microspheres and nanoflowers are synthesized,which show promising electrocatalytic properties toward oxygen and hydrogen evolution reactions(OER/HER).Such surface self-organized microstructure with accessible active sites make a significant contribution to the enhanced electrochemical activity,and hybridizing cobalt oxide with cobalt pyrophosphates and carbon can result in enhanced OER performance through synergistic catalysis.Among all nanostructures,the obtained microspherical CoPO@C/NF-3 catalyst exhibits excellent catalytic activities for OER and HER in 1.0 M KOH,affording an anodic current density of 10 mA cm^-2 at overpotentials of 293 mV for OER and 93 mV for HER,with good long-time stability.This work offers a practical route for engineering the high-performance electrocatalysts towards efficient energy conversion and storage devices.     

Optimizing the electronic structure of Fe-doped Co3O4 supported Ru catalyst via metal-support interaction boosting oxygen evolution reaction and hydrogen evolution reaction

Metal-support interaction(MSI) is an efficient way in heterogeneous catalysis and electrocatalysis to modulate the electronic structure of metal for enhanced catalytic activity. However, there are still great challenges in promoting the hydrogen evolution reaction(HER) and oxygen evolution reaction(OER) simultaneously by this way. Herein, Fe-doped Co₃O₄ supported Ru(Ru/FeCo) catalysts are synthesized by MSI strategies to further improve the electrocatalytic activity and sta...