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1.
Monodisperse nickel phosphide (Ni2P) nanorods and nanoparticles were synthesized by one step solution-phase route, in which the mixture of trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP) was used as solvent, capping agent and phosphor source. The morphologies of the Ni2P nanocrystals were controlled simply by varying the dropping rate of metal source. The as-prepared Pt-free Ni2P nanocrystals exhibit the enhanced electrocatalytic activity toward hydrogen evolution reaction (HER) compared to pure commercial Ni nanoparticles. Therefore, the obtained Ni2P nanocrystals appear to be promising non precious metal electrocatalysts for HER.  相似文献   

2.
The effect of rare earth compound, Gd2O3, on the microstructure and the hydrogen evolution property of Ni–Co alloy electrode was studied. The morphology and microstructure were characterized by SEM and XRD, respectively, and the electrocatalytic efficiency was evaluated on the basis of electrochemical data obtained from steady-state polarization curves, Tafel curves and electrochemical impedance spectroscopy measurements carried out in 0.50 M Na2SO4+0.10 M H2SO4 solution. It was found that the embedded Gd2O3 particles largely enhanced the electrocatalytic activity of Ni–Co alloy electrode to hydrogen evolution reaction.  相似文献   

3.
The present article reports the synthesis of hybrid structure along with non-precious cobalt-disulfide. A simple hydrothermal method was used to fabricate multi-faceted CoS2 introduced graphene aerogels. Studies on electrocatalytic activity showed that the presence of CoS2 facets along with graphene aerogel played a prominent role in the enhancement of proton reduction to hydrogen gas. The CoS2/graphene aerogel hybrid sample exhibits extremely low overpotential (160 mV vs. RHE), and high current density for HER in acidic solution. The activity enhancement can be attributed to increasing the active electrochemical surface area of graphene aerogel and faceted particles inside the 3D matrix of graphene. Furthermore, the CoS2/graphene hybrid retained its high activity even after 1000 cycles of cyclic voltammetry scans, signifying longer stability under acidic condition. The results suggest that CoS2/graphene aerogel hybrids show their potential application to hydrogen evolution reaction.  相似文献   

4.
A pre-treatment technique was developed to facilitate the electroless deposition of Pd layers onto ZrO2-TiO2 ceramic membrane surfaces in the preparation of novel multi-functional porous membranes. Surface functionalization using an aqueous solution of γ-aminopropyltriethoxysilane (γ-APTES) aided the surface immobilization of the Pd activation particles and the subsequent electroless deposition of metal layers onto the hydroxyl-rich membrane surface. The attractiveness of γ-APTES functionalization, in the electroless deposition of metal layers, was thus demonstrated. Characterization techniques employed in the structural study of the surface-modified membranes included SEM, EDS, dynamic analysis in micro-PIXE, and XRD. Special membrane techniques such as electrokinetic analysis and single-gas permeation measurements were also used in the study of surface modification. These membranes were developed for application in tasks associated with the hydrogen economy.  相似文献   

5.
Fe based oxides are considered as a promising catalyst for the oxygen evolution reaction (OER) due to their low cost and high stability. Here, based on density functional theory calculations, the electrocatalytic behaviors of pure and metal (Ni, Co) doped Fe-terminated Fe2O3(0001) are investigated. The potential-limiting step for OER is determined as the formation of O* by dehydrogenating surface hydroxyl and it is suggested that the doping enhances the catalytic activity of Fe2O3(0001) by reducing the free energy change of rate limiting step on doped Ni or Co atom. Especially, the calculated over-potential of Co-doped Fe2O3 (0001) surface is about 0.63 eV on Co site, which is comparable with the theoretical over-potential of 0.56 eV for RuO2.  相似文献   

6.
The electrocatalytic splitting of water via hydrogen evolution reaction (HER) is one of the most efficient technologies for hydrogen production, while the massive consumption of precious Pt‐based catalysts hinders its commercialization, bringing an urgent task to explore low‐cost and earth‐abundant alternatives. Herein, a cost‐efficient system composed of metal Pt/molybdenum disulphide (MoS2) nanosheets hybrids for the HER by auxiliary of solar light is reported. The uniformly Pt nanoparticle decorated MoS2 sheets can be easily obtained under hydrothermal condition using oleylamine as capping agent and N,N‐dimethylmethanamide (DMF) as intercalation molecule for MoS2 exfoliation. The Pt/MoS2 hybrid shows a significantly enhanced HER activity compared with bare MoS2 due to enhancing conductivity and reducing overpotential by electron transport between Pt and MoS2. As a result, a Tafel slope of 38 mV per decade is obtained, suggesting a highly efficient Volmer–Heyrovsky reaction of hydrogen evolution.  相似文献   

7.
The active catalysts for methane formation from the gas mixture of CO2 + 4H2 with almost 100% methane selectivity were prepared by reduction of the oxide mixture of NiO and ZrO2 prepared by calcination of aqueous ZrO2 sol with Sm(NO3)3 and Ni(NO3)2. The 50 at%Ni-50 at%(Zr-Sm oxide) catalyst consisting of 50 at%Ni-50 at%(Zr + Sm) with Zr/Sm = 5 calcined at 650 or 800 °C showed the highest activity for methanation. The active catalysts were Ni supported on tetragonal ZrO2, and the activity for methanation increased by an increase in inclusion of Sm3+ ions substituting Zr4+ ions in the tetragonal ZrO2 lattice as a result of an increase in calcination temperature. However, the increase in calcination temperature decreased BET surface area, metal dispersion and hydrogen uptake due to grain growth. Thus, the optimum calcination temperature existed.  相似文献   

8.
The continually worsening energy crisis has stimulated research into energy conversion technology to produce pure hydrogen, H2. Transition metal-based compounds have attracted great attention as electrocatalysts for hydrogen evolution reaction (HER) as alternatives to commercial, high-cost, and scarce noble metal-based catalysts. In this work, a 3D flower-like NiS2/MoS2 is synthesized with the advantages of a three-dimensional (3D) morphology and the compositing of different metal compounds, thus leading to enhanced electrocatalytic performance. The structure of 3D flower-like NiS2/MoS2 augments the specific surface areas resulting from nanoplate assemblies as well as the heterointerface ascribed to two different phases of NiS2 and MoS2. These characteristics are confirmed by electrocatalytic measurements of the lower overpotential of 165 mV at 10 mA/cm2 with high charge transfer ability, thus demonstrating the structure's potential for advanced electrocatalysts for the HER.  相似文献   

9.
电催化CO2还原反应可以产生HCOOH和CO,目前该反应是将可再生电力转化为化学能存储在燃料中的最有前景的方法之一. SnO2作为将CO2转换为HCOOH和CO的良好催化剂,其反应发生的晶面可以是不同的. 其中(110)面的SnO2非常稳定,易于合成. 通过改变SnO2(110)的Sn:O原子比例,得到了两种典型的SnO2薄膜:完全氧化型(符合化学计量)和部分还原型. 本文研究了不同金属(Fe、Co、Ni、Cu、Ru、Rh、Pd、Ag、Os、Ir、Pt和Au)掺杂的SnO2(110),发现在CO2还原反应中这些材料的催化活性和选择性是不同的. 所有这些变化都可以通过调控(110)表面中Sn:O原子的比例来控制. 结果表明,化学计量型和部分还原型Cu/Ag掺杂的SnO2(110)对CO2还原反应具有不同的选择性. 具体而言,化学计量型的Cu/Ag掺杂的SnO2(110)倾向于产生CO(g),而部分还原型的表面倾向于产生HCOOH(g). 此外,本文还考虑了CO2还原的竞争析氢反应. 其中Ru、Rh、Pd、Os、Ir和Pt掺杂的SnO2(110)催化剂对析氢反应具有较高的活性,其他催化剂对CO2还原反应具有良好的催化作用.  相似文献   

10.
采用等体积浸渍法制备了一系列负载型Ni基催化剂,利用XRD、H2-TPR、NH3-TPD 等技术表征了催化剂的理化特性,考察了载体(CMK-3、SiO2ZrO2、MgO、Al2O3)、助剂(Cu、Ce、Fe)对Ni基催化剂理化特性的影响,测试了230 oC、0.1 MPa冷压下催化剂对邻甲酚原位加氢反应的性能.结果表明,在负载型镍基催化剂作用下,甲醇水相重整制氢反应可以与邻甲酚的原位加氢反应相耦合;以CMK-3为载体的催化剂活性明显优于其他三种载体,邻甲酚的转化率为45.35%;助剂的添加对催化剂性能影响显著,Fe 的引入使原位加氢体系的转化率降至40.49%,助剂Ce、Cu的加入提高了Ni/CMK-3催化剂的原位加氢反应性能,转化率分别提高至64.6%、66.8%,Cu的添加改变了产物的分布,在产物中出现了新产物甲苯;同时探讨原位加氢反应路径及反应机理.  相似文献   

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