Basicity and Electrolyte Composition Dependent Stability of Ni-Fe-S and Ni-Mo Electrodes during Water Splitting

Non-noble metal electro-catalysts for water splitting are highly desired when we are moving towards a society where green electrons are becoming abundantly available, offering clear prospects to make our society more sustainable. In this work, Ni−Fe−S is reported as a high performing anode material for the water splitting reaction, operating at low overpotentials and showing high apparent stability. Furthermore, Ni−Mo electrodes are developed on metallic foam substrates and optimized in terms of their performance. The Ni−Fe−S material as anode, combined and integrated with Ni−Mo as cathode in a cell configuration, splits water at 10 mA cm⁻² and a potential of 1.55 V. Similar to previous reports, we confirm that Mo leaches from Ni−Mo/Ni foam electrodes. Cycling tests and ICP-AES measurements show that the stability of Ni−Fe−S is apparent, and that in reality S is leaching from the material as was already suggested in literature. We expand on this knowledge and show that the leaching of S is dependent on both pH and the cation used during electrocatalysis. Furthermore, we find that applying an oxidative potential is in truth stabilizing towards S and that the alkalinity causes leaching. S was furthermore mobile and found to segregate towards the surface. Finally, using too low pH values (11 and lower) result in the passivating hydroxide metal layers being destroyed and the Ni−Fe−S dissolving completely.     

Novel Nickel Redox Polymer as an Efficient Electrode Material for Electrochemical Sensing

A novel redox polymer comprised of poly(3,4‐ethylenedioxythiophene) (PEDOT) and ethylenediamine tetraacetic acid‐Ni²⁺ (EDTA‐Ni) complex serving as doping anions has been synthesised by a facile one‐step electrochemical approach and utilized as an efficient electrode material for sensitive luteolin detection. The morphology, chemical structure and composition of the redox polymer were analyzed by SEM, UV‐vis and FT‐IR spectrum. Electrochemical tests revealed that the redox polymer was highly electrochemically reversible and exhibited good electrocatalytic activity to the redox reactions of luteolin with a linear range covering from 1 nM to 10 µM with a low detection limit of 0.3 nM of luteolin.     

6-(3-氨基苯基)-4, 5-二氢哒嗪-3(2H)-酮的合成

以苯、丁二酸酐为原料,经傅克酰基化,硝化,与水合肼反应三步反应合成6-(3-氨基苯基)-4,5-二氢哒嗪-3(2H)-酮(1),总收率为58.3%。由3-(3-硝基苯甲酰基)丙酸(3)合成化合物1的过程中,在雷尼镍(Raney Ni)的催化下与水合肼反应,一步完成了苯环上硝基的还原和成环。重点考察了该步反应的物料配比、反应时间对产率的影响。结果表明,水合肼与化合物3的摩尔比11.7∶1,回流反应4 h,产率为82.7%。     

Coking-resistant Ni-ZrO2/Al2O3 catalyst for CO methanation

Highly coke-resisting Zr O2-decorated Ni/Al2O3 catalysts for CO methanation were prepared by a two-step process. The support was first loaded with Ni O by impregnating method and then modified with Zr O2 by deposition-precipitation method(IM-DP). Nitrogen adsorptiondesorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, H2 temperatureprogrammed reduction and desorption, NH3temperature-programmed desorption, and zeta potential analysis were employed to characterize the samples. The results revealed that, compared with the catalysts with the same composition prepared by co-impregnation(CI) and sequential impregnation(SI) methods, the Ni/Al2O3 catalyst prepared by IM-DP showed much enhanced catalytic performance for syngas methanation under the condition of atmospheric pressure and a high weight hourly space velocity of 120000 m L g-1 h-1. In a 80 h life time test under the condition of 300–600°C and 3.0 MPa, this catalyst showed high stability and resistance to coking, and the amount of deposited carbon was only 0.4 wt%. On the contrary, the deposited carbon over the catalyst without Zr O2 reached 1.5 wt% after a 60 h life time test. The improved catalytic performance was attributed to the selective deposition of Zr O2 nanoparticles on the surface of Ni O rather than Al2O3, which could be well controlled via changing the electrostatic interaction in the DP procedure. This unique structure could enhance the dissociation of CO2 and generate surface oxygen intermediates, thus preventing carbon deposition on the Ni particles in syngas methanation.     

电感耦合等离子发射光谱法测定镍铁中Si,Mn,P,Ni

建立ICP–AES法测定新型材料镍铁中的Si,Mn,P,Ni元素的方法。考察了镍铁基体和共存元素对测定结果的影响。通过基体匹配消除基体干扰,确定各待测元素谱线为Mn 293.930 nm,P 178.280 nm,Ni 231.604 nm,Si251.611 nm。Si,Mn,P,Ni的检出限分别为0.06,0.04,0.08,0.04 mg/L,测定结果的相对标准偏差均小于5%(n=11),加标回收率在95%~105%之间。该方法操作简便、测定结果准确可靠,可用于镍铁中Si,Mn,P,Ni的含量测定。     

Convenient and Scalable Process for the Preparation of Indole via Raney Nickel–Catalyzed Hydrogenation and Ring Closure

An efficient and practical method for the synthesis of indole as a key starting material for many useful chemicals is described. Using 2-nitrotoluene as starting material, hydroxymethylation with formaldehyde under alkaline conditions gave 2-(2-nitrophenyl)ethanol on a large scale. Raney Ni catalyst was used for both reduction of the nitro group as well as for the indole formation. The overall yield was 78% from 2-nitrotoluene.     

求解非光滑方程组的三次正则化方法

考虑求解非光滑方程组的三次正则化方法及其收敛性分析.利用信赖域方法的技巧,保证该方法是全局收敛的.在子问题非精确求解和BD正则性条件成立的前提下,分析了非光滑三次正则化方法的局部收敛速度.最后,数值实验结果验证了该算法的有效性.     

有机共沉淀-火焰原子吸收光谱法测定高纯稀土氧化物中痕量铅镉钴镍铁铜

本文研究了吡咯啶二硫代氨基甲酸铵(APDC)共沉淀痕量铅镉钴镍铁铜的最佳条件;金属-PDC配合物的稳定性及共存元素的干扰等。沉淀溶解于小体积的甲基异丁酮(MIBK)中,采用微量进样技术,将有机相直接喷入空气-乙炔火焰,原子吸收光谱法测定之。该法已成功地应用于荧光级氧化镧和氧化钇中题示元素的测定。     

Ni deposition on the pentagonal surface of an icosahedral Al-Pd-Mn quasicrystal

We have evaporated Ni on the pentagonal surface of an icosahedral Al-Pd-Mn quasicrystal kept at room temperature. At the initial stage of growth, Ni intermixes with the substrate surface. Subsequently, Al from the quasicrystal matrix migrates to growing layers. The modified chemical composition in an initially icosahedral region near the surface induces a structural transformation. An Al-Pd-Mn alloy is formed which consists of five cubic domains with dimensions in the nm-range exposing their (1 1 0) faces parallel to the surface. These domains are azimuthally rotated by 2π/5 with respect to each other and aligned with symmetry directions of the icosahedral substrate. Al-Mn-Ni, Al-Ni, and Ni overlayers adopt both structure and orientation of these domains which stabilises Ni in a novel body-centred cubic phase. Ni-rich overlayers exhibit out-of-plane magnetic ordering.     

Electrodeposition of Zn–Ni alloys from sulfate bath

The electrodeposition of zinc–nickel (Zn–Ni) alloys from sulfate baths has been studied at different deposition times and H₂SO₄ and NiSO₄ concentrations; various characteristics have been observed during alloy deposition and dissolution. The deposit has been investigated by using scanning electron microscopy (SEM) and X-ray diffractometry. Cyclic voltammetry and galvanostatic measurements during electrodeposition have been conducted. Electrochemical and surface analysis indicate that deposition takes place with the formation of two different structures corresponding to γ-phase and δ-phase zinc–nickel alloys. During anodic part of the cyclic voltammetry of the alloys, a reduction process has been observed, which may be due to hydrogen evolution. With the increase of nickel concentration in the bath, the amount of γ-phase increases, as indicated by the relative increase in the height of the peaks in the X-ray patterns and anodic peaks in the cyclic voltammograms. Also, the corrosion resistance of the zinc–nickel alloy has been improved with an increased concentration of nickel. Under these experimental conditions the electrodeposition of the alloys is of anomalous type.