非晶态镍磷镀层析氢阴极活性的控制与机理

非晶态Ni-P类合金镀层具有很好的耐蚀性,在碱性溶液中具有较高的析氢反应催化活性,能降低析氢过电位,节约能源,是一种有很好应用前景的阴极材料.论述了非晶态Ni-P镀层的P含量、厚度、制备条件、添加第3种元素及镀后处理对镀层电极活性的影响.并总结了Ni-P类非晶态合金镀层的电极催化机理.     

非晶态MmNi5.20合金薄膜的制备及析氢反应电催化性能的研究

用离子束溅射法制备非晶态ＭｍＮｉ＿（５．２０）合金薄膜。该非晶态合金薄膜在３０ｗｔ％ＫＯＨ，７０℃作析氢反应电极。实验结果表明，该电极不但具有良好的析氢电催化活性和电化学稳定性，而且具有很好的抗氢脆和抗粉化能力。交流阻抗分析表明，非晶态ＭｍＮｉ＿（５．２０）合金电极析氢反应过程主要由电化学反应步骤控制。     

非晶态Ni－Mo－Fe合金作电解水析氢反应电极

用电沉积法制备非晶态Ｎｉ＿（４１．５）Ｍｏ＿（３５．５）Ｆｅ＿（２３．０）合金电极。该合金电极在３０ｗｔ％ＫＯＨ溶液，７０℃作析氢反应阴极，实验研究结果表明，合金电极对氢的析出反应具有优良的电催化性能。在２００ｍＡ／ｃｍ￣２电流密度下析氢反应过电位约９０ｍＶ，在连续电解和间歇电解条件下有良好的电化学稳定性。     

Combining Highly Dispersed Amorphous MoS3 with Pt Nanodendrites as Robust Electrocatalysts for Hydrogen Evolution Reaction

Surface modification of electrocatalysts to obtain new or improved electrocatalytic performance is currently the main strategy for designing advanced nanocatalysts. In this work, highly dispersed amorphous molybdenum trisulfide-anchored Platinum nanodendrites (denoted as Pt-a-MoS₃ NDs) are developed as efficient hydrogen evolution electrocatalysts. The formation mechanism of spontaneous in situ polymerization MoS₄²⁻ into a-MoS₃ on Pt surface is discussed in detail. It is verified that the highly dispersed a-MoS₃ enhances the electrocatalytic activity of Pt catalysts under both acidic and alkaline conditions. The potentials at the current density of 10 mA cm⁻² (η₁₀) in 0.5 m  sulfuric acid (H₂SO₄) and 1 m  potassium hydroxide (KOH) electrolyte are −11.5 and −16.3 mV, respectively, which is significantly lower than that of commercial Pt/C (−20.2 mV and −30.7 mV). This study demonstrates that such high activity benefits from the interface between highly dispersed a-MoS₃ and Pt sites, which act as the preferred adsorption sites for the efficient conversion of hydrion (H⁺) to hydrogen (H₂). Additionally, the anchoring of highly dispersed clusters to Pt substrate greatly enhances the corresponding electrocatalytic stability.     

Deformable Catalytic Material Derived from Mechanical Flexibility for Hydrogen Evolution Reaction

Deformable catalytic material with excellent flexible structure is a new type of catalyst that has been applied in various chemical reactions, especially electrocatalytic hydrogen evolution reaction(HER). In recent years, deformable catalysts for HER have made great progress and would become a research hotspot. The catalytic activities of deformable catalysts could be adjustable by the strain engineering and surface reconfiguration. The surface curvature of flexible catalytic materials is closel...     

An Overview of Hydrogen Interaction with Amorphous Alloys

Theories, experimental results and applications associated with hydrogen behavior in amorphous metals and alloys are reviewed. An emphasis is made on the potential use of these advanced materials for hydrogen storage technology. Therefore, several properties that are especially relevant for such applications are assessed. These include structural models for hydrogen occupancy, sorption characteristics, solubility, diffusion behavior and thermal stabilities. Hydrogen effects on the mechanical properties and fracture modes of glassy metals are also presented, and possible mechanisms of hydrogen embrittlement are discussed. Similarities and differences between hydrogen behavior in amorphous and crystalline metals and alloys are discussed in detail.     

非晶态镁基储氢合金的研究进展

综述了非晶态镁基储氢合金的研究现状和最新进展.简要分析了制约该合金实用化的主要因素,并针对存在的问题介绍了机械球磨工艺、多元合金化、复合以及表面改性对合金的形成及性能,特别是对合金的放电容量和循环稳定性的影响,同时指出了今后研究工作的重点和方向.     

Interstitial Hydrogen Atom to Boost Intrinsic Catalytic Activity of Tungsten Oxide for Hydrogen Evolution Reaction

Tungsten oxide (WO₃) is an appealing electrocatalyst for the hydrogen evolution reaction (HER) owing to its cost-effectiveness and structural adjustability. However, the WO₃ electrocatalyst displays undesirable intrinsic activity for the HER, which originates from the strong hydrogen adsorption energy. Herein, for effective defect engineering, a hydrogen atom inserted into the interstitial lattice site of tungsten oxide (H_0.23WO₃) is proposed to enhance the catalytic activity by adjusting the surface electronic structure and weakening the hydrogen adsorption energy. Experimentally, the H_0.23WO₃ electrocatalyst is successfully prepared on reduced graphene oxide. It exhibits significantly improved electrocatalytic activity for HER, with a low overpotential of 33 mV to drive a current density of 10 mA cm⁻² and ultra-long catalytic stability at high-throughput hydrogen output (200 000 s, 90 mA cm⁻²) in acidic media. Theoretically, density functional theory calculations indicate that strong interactions between interstitial hydrogen and lattice oxygen lower the electron density distributions of the d-orbitals of the active tungsten (W) centers to weaken the adsorption of hydrogen intermediates on W-sites, thereby sufficiently promoting fast desorption from the catalyst surface. This work enriches defect engineering to modulate the electron structure and provides a new pathway for the rational design of efficient catalysts for HER.     

非晶态合金焊接的研究进展

综述了近几年国内外非晶态合金在焊接方面的研究进展,简要分析了将大块非晶合金焊接成功的原因.目前可以成功焊接大块非晶合金的方法有:高压压实法、摩擦焊、闪光电阻焊、电子束焊、爆炸焊、激光焊.其中前两种焊接属于固相焊接,成功的原因主要是:块体非晶合金过冷液相区的热稳定性和超塑性.而其他几种属于液相焊接,成功的原因主要是:(1)非晶合金具有大的非晶形成能力;(2)焊接的能量高且集中,因而加热和冷却速度快于这些合金的临界冷却速度.大块非晶合金的焊接成功地推动了大块非晶合金在工程材料方面的应用.     

Revealing the Contribution of Individual Factors to Hydrogen Evolution Reaction Catalytic Activity

For the electrochemical hydrogen evolution reaction (HER), the electrical properties of catalysts can play an important role in influencing the overall catalytic activity. This is particularly important for semiconducting HER catalysts such as MoS₂, which has been extensively studied over the last decade. Herein, on‐chip microreactors on two model catalysts, semiconducting MoS₂ and semimetallic WTe₂, are employed to extract the effects of individual factors and study their relations with the HER catalytic activity. It is shown that electron injection at the catalyst/current collector interface and intralayer and interlayer charge transport within the catalyst can be more important than thermodynamic energy considerations. For WTe₂, the site‐dependent activities and the relations of the pure thermodynamics to the overall activity are measured and established, as the microreactors allow precise measurements of the type and area of the catalytic sites. The approach presents opportunities to study electrochemical reactions systematically to help establish rational design principles for future electrocatalysts.     

非晶态Fe-Mo合金在碱性溶液中的电催化析氢活性

研究了电沉积制备的非晶态Fe-Mo合金(组成分别为Fe82Mo18、Fe74Mo26和Fe71Mo29)电极在30％KOH溶液中，303～343K的温度范围内的析氢催化性能。三种非晶态合金都显示出较好的催化析氢活性。温度为343K，析H2电流密度为300nA／cm^2时的析H2过电位为150～157mV。非晶态Fe82Mol8、Fe74Mo26和Fe71Mo29合金上析H2反应的表观活化能分别为57．18，47．33，102．28kJ／mol。