钼基析氢反应电催化剂的研究进展

电催化析氢反应作为一种绿色、可持续的制备氢气方法,受到了广泛关注. 近年来,非贵金属析氢催化剂以其低成本和相对高的催化活性取得了较快的研究进展,其中,钼基纳米催化剂目前已成为电催化析氢中最受关注的研究热点之一. 本文综述了钼基碳化物、磷化物、氮化物以及硫化物在电催化析氢反应中的催化机理和研究进展,分析了提高析氢催化活性的方法,并对钼基非贵金属催化剂的发展趋势进行了展望.     

镍铜合金立方体纳米晶的脉冲电沉积及电催化析氢性能

以泡沫镍(NF)为基体, 采用常规脉冲伏安法合成了独立分相的金属Ni, Cu为主晶相、 平均粒径为70 nm的规则立方体结构镍铜合金电催化剂(NiCu/NF). 在电催化析氢反应中, NiCu/NF表现出优良的催化活性和优异的催化稳定性, 在电流密度为10 mA/cm ²时, 在1.0 mol/L KOH溶液中需要的析氢过电位仅为86 mV, 催化24 h的电位波动仅为12 mV. 二级复合纳米立方体结构使NiCu/NF展现出15.5倍于空白NF的电化学活性面积(ECSA), 为电催化反应提供了大量催化活性位点, 也为电极表面的电荷传输、 物质传递提供了充足的通道; Cu的引入以及NiO/Ni异质结的形成改善了邻近Ni原子的活性, 使镍基材料本征析氢活性得以改善, 三者协同促进了NiCu/NF电催化活性的提升. NiCu/NF电极在析氢过程中遵循Volmer-Heyrovsky机理, 反应速率由电极表面吸附氢原子的电化学脱附过程决定.     

镍基电催化析氢催化剂的研究进展

氢能是目前世界上公认的清洁能源之一,如何有效的可持续的产氢是人们步入氢能社会首要解决的问题.研发低成本,高性能,高稳定性的电催化析氢催化剂对提升产氢技术,促进氢能经济的发展具有重要意义.本文综述了近几年发展的镍基电催化析氢催化剂,重点介绍了镍的氧化物,镍的双层氧化物/氢氧化物,硒化物,硫化物等电催化析氢催化剂的研究和发展情况,对它们的合成方法、结构特性、催化活性、稳定性能以及微观结构和析氢性能之间的关系进行深入的探讨,并一一举例说明.     

Ni(OH)_2/Ni/g-C_3N_4复合材料:一种高效的析氢电催化剂（英文）

高效析氢催化剂的制备仍是目前亟待解决的重要课题。本研究采用液相浸渍原位还原法制备了Ni(OH)_2/Ni/gC_3N_4复合催化剂,并与碳纸(CP)组合作为微生物电解电池(MEC)的阴极。采用SEM、TEM、XRD、XPS和电化学分析等技术对所制备的催化剂样品的结构性质和析氢电催化性能进行了分析研究。结果表明,Ni(OH)_2/Ni/g-C_3N_4催化剂在100 A/cm~2的电流密度驱动下具有优秀的析氢过电位(1881 mV)、较低的电荷转移电阻(10.86Ω)和较低的塔费尔斜率(44.3 mV/dec),其电化学活性优于纯g-C_3N_4催化剂和CP,甚至可与Pt催化剂媲美。     

原位生长Pd/Ni(OH)2/NF复合催化剂及其析氢性能

采用水热合成法在泡沫镍上原位构建了低贵金属含量的钯/氢氧化镍纳米复合催化剂（Pd/Ni（OH）₂/NF）。通过扫描电镜,能谱仪,X射线衍射仪和X射线光电子谱仪等分析技术表征了催化剂的形貌和微观结构;运用线性扫描伏安法,电化学阻抗谱和计时电流法等手段研究了催化剂的催化析氢性能。实验结果显示复合催化剂具有特殊的微观构型,超薄的Ni（OH）₂薄片生长在泡沫镍表面,纳米尺寸的钯均匀地镶嵌在氢氧化镍薄片中。催化剂表面的氢氧化镍有利于促进水的解离,加快氢中间体的形成;均匀分散的钯极易吸附解离的氢中间体,快速地复合成氢气分子。我们发现复合催化剂能协同加快析氢反应过程,极大地降低析氢过电位,提高了析氢活性。此外,复合催化剂原位生长在泡沫镍上,有效地提高了催化电极的稳定性。     

优化金属磷化物电催化析氢性能的策略

日益严重的能源危机和环境污染问题使得探索清洁的可再生能源载体及减少对传统化石燃料的过度依赖成为人们面临的一项重要任务.因此,各种可持续能源如太阳能、风能、海洋能和生物质能等得到了广泛研究并取得了一定的进展.然而,这些能源因存在间歇性和不稳定性等缺点阻碍了其实际应用.近年,氢气作为一种能源载体,以其高能量密度和无碳排放的优点引起了人们的广泛关注,被认为是缓解日益严重的污染问题的最有前途的环保能源.对比目前采用的天然气热解和煤炭气化等传统制氢策略,电催化水裂解由于催化效率高,制氢纯度高和不产生温室气体,被认为是高效、环保、可持续的制氢策略.电催化水裂解由两个独立的半反应组成,分别是析氢反应和析氧反应.析氢反应作为水裂解的一个半反应,在降低制氢成本及提高产氢催化效率方面起着关键作用.然而,目前的核心问题之一是要开发高效的析氢电催化剂,以加快反应速度.目前,铂和铂基纳米材料被认为是高效的析氢电催化剂,但是其稀缺性和高成本阻碍了大规模实际应用.金属磷化物由于具有较高的本征活性并且在不同的电解质中都具有良好的电催化析氢性能,被证明是一种优良的析氢电催化剂.此外,与普通催化剂相比,金属磷化电催化剂还具有合成简便、效率高、成本低、省时等优点.本文详细介绍了近年人们在金属磷化物用于电催化析氢研究中取得的进展.首先,介绍了电催化析氢反应机理,金属磷化物的结构及作用,并对其优缺点进行了总结;随后,综述了金属磷化物的合成方法,包括后处理、原位生成和电沉积策略,并对不同方法进行了比较和讨论.此外,从元素掺杂、界面工程、空穴工程、修饰特定载体、构建特定纳米结构、设计双或多金属磷化物和其他发展的新方法等七个方面详细总结了促进金属磷化物电催化活性的多种策略,并进行了对比和讨论.最后,归纳了金属磷化物在电催化析氢应用中存在的问题和面临的挑战,并对未来的研究发展提出了展望.     

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.     

镍钒合金电沉积及其析氢电催化性能的研究

镍钒合金电沉积及其析氢电催化性能的研究林文修王树喜（福建师范大学化学系福州３５０００７）关键词镍钒合金电镀电催化析氢反应对电化学的能量转换、电合成、金属沉积和防腐等具有重要意义，选择和探索优良的过渡金属电催化剂是研究析氢电催化阴极的主要方向。１９７８...     

镍基金属有机框架衍生的双功能电催化剂用于析氢和析氧反应（英文）

开发高活性、低成本的析氢反应和析氧反应电催化剂对于能源的可持续发展至关重要。金属有机框架衍生的纳米材料已经成为一类非常有前景的非贵金属双功能电催化剂,但是目前对镍基金属有机框架衍生的双功能电催化剂的深入研究并不全面,其催化活性和稳定性还有待进一步提高。本文制备了一种棒状多孔碳负载镍纳米颗粒的新型电催化剂,并将其用作电催化析氢和析氧反应。实验研究结果表明该类电催化剂表现出优异的析氢和析氧反应活性和长期稳定性,在10 mA·cm~(-2)的电流密度下,析氢反应和析氧反应的过电位分别为120和350 mV。我们认为:材料可控的纳米结构和均匀分布的活性位点共同提升了复合材料的电催化性能。     

Fe/Co和Ni/Co镍黄铁矿型析氢反应电催化剂

作为析氢反应的电催化剂,富金属的过渡金属硫化物因能克服富硫金属催化剂所存在的如导电性有限和缺乏必要的纳米结构等不足,近年来受到越来越多的关注.本文介绍了具有镍黄铁矿型结构的三元富金属硫化物复合材料FexCo9-xS8和Ni_yCo_9-yS₈(x=y=0-4.5)的合成、表征及其电催化研究.首先,研究了二元钴化合物Co₉S₈中Co逐步被Fe或Ni取代直至4.5当量的变化过程.硫镍铁矿复合物中组分的变化有助于不同温度下酸性介质中的质子还原.其次,在还原电催化条件下,复合物中元素化学计量变化对其电化学活化/失活行为有决定性的影响.与Co₉S₈相比,Co缺陷复合材料表现出了更高的HER性能.Ni/Co化合物通常表现出比类似结构Fe/Co化合物更高的电催化析氢活性.     

直接甲醇燃料电池阴极耐甲醇Pd-Co/C电催化剂的制备与表征

以NaBH4为还原剂,采用共还原法和分步还原法制备了粒径分布均匀的Pd/C和Pd-Co/C电催化剂.X射线衍射、透射电镜、电化学循环伏安和旋转厕盘电极等表征结果表明,与Pd/C电催化剂相比,两种方法制备的Pd-Co/C电催化剂的晶格常数明显缩小,其中分步还原法制备的电催化剂不仅具有良好的氧还原活性,而且表现了良好的耐甲醇性能.     

直接甲醇燃料电池电催化剂性能衰减研究

通过单电池放电试验, 考察了直接甲醇燃料电池(DMFC)电催化剂的性能衰减情况. 透射电镜(TEM)和X射线衍射分析(XRD)结果表明, 放电试验后阳极电催化剂的粒径变化很小, 而阴极电催化剂的粒径则显著增大. DMFC内部的液相环境是促使Pt粒子聚结的主要原因. 阳极催化剂中Ru的存在抑制了Pt粒子的生长. 阳极和阴极电催化剂的电化学表面积(ECSA)在放电后都有所降低, 且下降幅度均高于比表面积(SSA)的下降幅度. 放电过程中阳极电催化剂发生了Ru的流失.     

PtCeOx/C as a novel methanol-tolerant electrocatalyst of oxygen reduction for direct methanol fuel cells

A prominent methanol-tolerant characteristic of the PtCeO_x/C electrocatalyst was found during oxygen reduction reaction process. The carbon-supported platinum modified with cerium oxide (PtCeO_x/C) as cathode electrocatalyst for direct methanol fuel cells was prepared via a simple and effective route. The synthesized electrocatalysts were characterized by X-ray diffraction and transmission electron microscopy. It was found that the cerium oxide within PtCeO_x/C present in an amorphous form on the carbon support surface and the PtCeO_x/C possesses almost similar disordered morphological structure and slightly smaller particle size compared with the unmodified Pt/C catalyst.     

Performance of Pd Electrocatalyst Supported on a Physical Mixture Indium Tin Oxide–carbon for Glycerol Electro–oxidation in Alkaline Media

Palladium electrocatalysts, supported on Vulcan XC 72 carbon and indium tin oxide (ITO) with different ratios, were prepared by borohydride reduction method and analysed for glycerol electro‐oxidation application in the presence of KOH solution. Transmission electron microscopy (TEM) and X‐ray diffraction (XRD) techniques were used to characterize the particle size and crystal electrocatalyst structures, whereas their catalytic activities regarding the glycerol electro‐oxidation were evaluated by cyclic voltammetry (CV), chronoamperometry and tested in a direct alkaline glycerol fuel cell (DGFC) by electrochemical techniques. Micrographs results showed that the ITO presence promotes a large agglomeration of particles. Pd/C–ITO electrocatalysts showed peaks associated with the face‐centered cubic (fcc) structure of palladium and several others peaks associated with ITO used as support. Similar performance was found on all Pd/C–ITO electrocatalysts where measurements in CV were compared to Pd/C and Pd/ITO with Pd/C–ITO 50:50 chronoamperometry, presenting a better performance for glycerol electro‐oxidation. When using Pd/C–ITO 85:15 electrocatalyst and 1.0 mol L⁻¹ glycerol at 90 °C, the maximum power density found was 2,1 times higher than that obtained using Pd/C and Pd/CITO electrocatalysts. Therefore, the physical mixture of ITO and carbon, to be used as a support improves the electrocatalytic activity for glycerol oxidation reaction.     

Integrated Ni_2P nanosheet arrays on three-dimensional Ni foam for highly efficient water reduction and oxidation

The large-scale synthesis of efficient nonprecious bifunctional electrocatalysts for overall water splitting is a great challenge for future renewable energy conversion systems. Herein, Ni_2P nanosheet arrays directly grown on three-dimensional(3 D) Ni foam(Ni P/NF) are fabricated by hydrothermal treatment of metallic Ni foam with H_2O_2 solution and subsequent phosphidation with NaH_2PO_2. The Ni P/NF as electrocatalyst exhibits superior activities for both hydrogen evolution reaction(HER) and oxygen evolution reaction(OER). Most importantly, employing both as the cathode and anode for an alkaline water electrolyzer, Ni P/NF only requires a cell voltage of 1.63 V to reach a current density of 10 mV cm~(-2), together with stronger durability. Preliminary catalytic information suggests that the tailored 3 D superstructure and integrated electrode configurations afford improved active sties and enhanced electron/mass transfer,responding for the outstanding activity and stability.     

微乳法合成Pt/C、PtIr/C催化剂及其电化学性能表征

以碳纳米粉(XC-72R)作为载体,采用三种不同方法合成Pt/C负载型催化剂。利用X射线衍射(XRD)、透射电镜(TEM)、循环伏安法(CV)、恒电位测试(Potentiostatic)以及线性极化分析（Potentiodynamic polarization）等手段进行催化剂表征,结果表明,微乳法制得的负载型催化剂,活性组分的颗粒尺寸为5～10nm,且均匀地分散在载体表面,其电化学性能良好。而微乳法进一步制备的含不同比例的负载型的PtIr/C催化剂,其中以Pt85Ir15表现出更为较好的电化学综合性能。     

Platinum nanoparticles supported on zirconia–carbon black nanocomposites for methanol oxidation reaction

Platinum (Pt) nanoparticles supported on zirconia–carbon black nanocomposites (Zr–C), which annealed at different temperatures, used as Pt/Zr–C electrocatalysts for methanol oxidation reaction (MOR) are prepared and characterized in this study. Transmission electron microscope images and X-ray diffraction analysis showed that the diameters of Pt nanoparticles are around 3–4 nm. Electrocatalytic MOR performances of these Pt/Zr–C electrocatalysts are investigated by cyclic voltammetry, CO-stripping voltammetry, and chronoamperometry. All the Pt/Zr–C electrocatalysts synthesized in this study exhibited higher MOR efficiency than that of the commercial E-TEK Pt/C electrocatalyst, and the electrocatalyst using Zr–C support annealed at 300 °C, achieving the highest MOR efficiency among all the electrocatalysts.     

Carbon/titanium oxide supported bimetallic platinum/iridium nanocomposites as bifunctional electrocatalysts for lithium-air batteries

Platinum (Pt) and iridium (Ir) catalysts are well known to strongly enhance the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics, respectively. Pt–Ir-based bimetallic compounds along with carbon-supported titanium oxides (C–TiO₂) have been synthesized for the application as electrocatalysts in lithium oxygen batteries. Transition metal oxide-based bimetallic nanocomposites (Pt–Ir/C–TiO₂) were prepared by an incipient wetness impregnation technique. The as-prepared electrocatalysts were composed of a well-dispersed homogenous alloy of nanoparticles as confirmed by X-ray diffraction patterns and Fourier transform scanning electron microscopy analyses. The electrochemical characterizations reveal that the Pt–Ir/C–TiO₂ electrocatalysts were bifunctional with high activity for both ORR and OER. When applied as an air cathode catalyst in lithium-air batteries, the electrocatalyst improved the battery performance in terms of capacity, reversibility, and cycle life compared to that of cathodes without any catalysts.     

Synthesis and characterization of platinum monolayer oxygen-reduction electrocatalysts with Co–Pd core–shell nanoparticle supports

We synthesized Pt monolayer electrocatalysts for oxygen-reduction using a new method to obtain the supporting core–shell nanoparticles. They consist of a Pt monolayer deposited on carbon-supported Co–Pd core–shell nanoparticles with the diameter of 3–4 nm. The nanoparticles were made using a redox-transmetalation (electroless deposition) method involving the oxidation of Co by Pd cations, yielding a Pd shell around the Co core. The quality of the thus-formed core–shell structure was verified using transmission electron microscopy and X-ray absorption spectroscopy, while cyclic voltammetry was employed to confirm the lack of Co oxidation (dissolution). A Pt monolayer was deposited on the Co–Pd core–shell nanoparticles by the galvanic displacement of a Cu monolayer obtained by underpotential deposition. The total noble metal mass-specific activity of this Pt monolayer electrocatalyst was ca. 3-fold higher than that of commercial Pt/C electrocatalysts.     

铂基氧还原电催化剂的结构演变

质子交换膜燃料电池的商业化有望在不久的将来实现更清洁的能源社会.然而,氧还原反应缓慢的反应动力学和苛刻的条件对质子交换膜燃料电池的寿命和成本产生了巨大的挑战.之前大多数铂基催化剂的设计都将重点更多地放在提高活性上.随着质子交换膜燃料电池的商业化,寿命问题也受到了更多的关注.对整个生命周期中结构演变进行深入地了解,有助于...