Topic
Nickel
About: Nickel is a research topic. Over the lifetime, 79308 publications have been published within this topic receiving 1210058 citations. The topic is also known as: Ni & element 28.
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TL;DR: In this paper, a series of Ni/Al2O3 catalysts were synthesized using four different precursors, nickel nitrate, nickel chloride, nickel acetate, and nickel acetylacetonate.
Abstract: This paper describes an investigation regarding the influence of Ni precursors on catalytic performances of Ni/Al2O3 catalysts in glycerol steam reforming. A series of Ni/Al2O3 is synthesized using four different precursors, nickel nitrate, nickel chloride, nickel acetate, and nickel acetylacetonate. Characterization results based on N2 adsorption–desorption, X-ray diffraction, H2 temperature-programmed reduction, H2 chemisorption, transmission electron microscopy, and thermogravimetric analysis show that reduction degrees of nickel, nickel dispersion, and particle sizes of Ni/Al2O3 catalysts are closely dependent on the anion size and nature of the nickel precursors. Ni/Al2O3 prepared by nickel acetate possesses the moderate Ni reduction degree, high Ni dispersion, and small nickel particle size, which possesses the highest H2 yield. Reaction parameters are also examined, and 550 °C and a steam-to-carbon ratio of 3 are optimized. Moreover, coke deposition, mainly graphite species, leads to the deactivati...
162 citations
TL;DR: Nickel(II) complexes of bidentate N-heterocyclic carbene (NHC)/phosphane ligand L were prepared and structurally characterized, and the activities of 2 a are largely superior to those of other reported nickel NHC complexes and their palladium counterparts.
Abstract: Nickel(II) complexes of bidentate N-heterocyclic carbene (NHC)/ phosphane ligand L were prepared and structurally characterized. Unlike palladium, which forms [PdCl 2 (L)], the stable nickel product isolated is the ionic [Ni(L) 2 ]Cl 2 . These Ni II complexes are highly robust in air. Among different N-substituents on the ligand framework, the nickel complex of ligand L bearing N-1-naphthylmethyl groups (2a) is a highly effective catalyst for Suzuki cross-coupling between phenylboronic acid and a range of aryl halides, including unreactive aryl chlorides. The activities of 2 a are largely superior to those of other reported nickel NHC complexes and their palladium counterparts. Unlike the previously reported [NiCl 2 (dppe)] (dppe= 1,2-bis(diphenylphosphino)ethane), 2a can effectively catalyze the cross-coupling reaction without the need for a catalytic amount of PPh 3 , and this suggests that the PPh 2 functionality of hybrid NHC ligand L can partially take on the role of free PPh 3 . However, for unreactive aryl chlorides at low catalyst loading, the presence of PPh 3 accelerates the reaction.
162 citations
TL;DR: In this article, the authors reported the activity results obtained in steam-methane reforming (SMR) at 500 and 600°C using four nickel-based catalysts: (a) Ni/α-Al2O3 and Ni/SiO2, prepared by incipient wetness impregnation method and (b) Ni−Zn−Al and Ni−Mg−Al, prepared using coprecipitation method.
162 citations
01 Mar 1971
TL;DR: An electrochemical method has been used to determine the permeability,P, diffusion coefficient,D, and solubility,c, of hydrogen in alloys of the Fe-Ni system as discussed by the authors.
Abstract: An electrochemical method has been used to determine the permeability,P, diffusion coefficient,D, and solubility,c, of hydrogen in alloys of the Fe-Ni system The heats of activation for diffusion and the heats of solution have been derivedD falls from ≃10−4 sq cm per sec for pure iron to ≃10−10 sq cm per sec for 40 wt pct of Ni in the alloy Thereafter it rises slightly to that for pure nickel,c rises by about 103 between pure iron and 40 wt pct Ni, then remains constant up to pure nickel The resultantP doubles at 5 wt pct Ni and then falls by 103 times up to 40 wt pct Ni, afterwards rising slightly to that for pure nickel Between 0 and 40 wt pct Ni the dominant factor in controlling the value ofP is the fall of the mole fraction of the α phase in the alloy This hypothesis gives a reasonable quantitative calculation of theP-composition relation Between 40 and 100 wt pct, the crystallographic phase is allγ and the major effect is the bonding of hydrogen in the alloy, the small changes noted being reasonably calculable The negligible change of solubility in this region reflects the negligible change ind character of the alloy from 40 to 100 wt pct Ni The hydrogen permeability of Fe-Ni (5 wt pct) is greater than that of palladium atT > 200°C The corrosion rate and hydrogen permeability (hence, susceptibility to hydrogen embrittlement) pass through a minimum at about 50 wt pct Ni A remarkable parallelism exists between corrosion rate and hydrogen permeation in Fe-Ni alloys An interpretation is suggested
162 citations
TL;DR: In this article, the authors report the development of an iron-doped nickel disulfide nanoarray on Ti mesh (Fe0.1-NiS2 NA/Ti) via the sulfidation of its nickel-iron-layered double hydroxide precursor.
Abstract: Developing efficient water-splitting electrocatalysts, particularly for the anodic oxygen evolution reaction (OER), is an important challenge in energy conversion technologies. In this study, we report the development of iron-doped nickel disulfide nanoarray on Ti mesh (Fe0.1-NiS2 NA/Ti) via the sulfidation of its nickel–iron-layered double hydroxide precursor (NiFe-LDH NA/Ti). As a three-dimensional OER anode, Fe0.1-NiS2 NA/Ti exhibits remarkable activity and stability in 1.0 M KOH, with the requirement of a low overpotential of 231 mV to achieve 100 mA·cm−2. In addition, it exhibits excellent activity and durability in 30 wt.% KOH. Notably, this electrode is also efficient for the cathodic hydrogen evolution reaction under alkaline conditions.
161 citations