Electrochemical and thermal behavior of aluminum- and magnesium-doped spherical lithium nickel cobalt mixed oxides Li1−x(Ni1−y−zCoyMz)O2 (M = Al, Mg)

2003 ◽  
Vol 119-121 ◽  
pp. 178-183 ◽  
Author(s):  
S Albrecht ◽  
J Kümpers ◽  
M Kruft ◽  
S Malcus ◽  
C Vogler ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Mixed Oxides ◽  
Nickel Cobalt

Hydrogen Adsorption Capacity Investigation of Ni-Co-Al Mixed Oxides

2014 ◽  
Vol 917 ◽  
pp. 360-364 ◽  
Author(s):  
M. Abdus Salam ◽  
Suriati Sufian
Keyword(s):  
Hydrogen Adsorption ◽  
Mixed Oxides ◽  
Textural Properties ◽  
Metal Dispersion ◽  
Temperature Programmed Reduction ◽  
Oxide Formation ◽  
Nickel Cobalt ◽  
Icp Ms ◽  
Temperature Programmed ◽  
Adsorption Desorption

Micro-mesoporous mixed oxides containing nickel, cobalt and aluminum have been synthesized using conventional coprecipitation method. FESEM and HRTEM analyses demonstrated the flower and hexagonal plate-like nanostructured of mixed oxides. Different mixed oxide formation, homogenous metal dispersion, textural properties were investigated using XRD, ICP-MS and BET (N2 adsorption-desorption) techniques. nanostructured mixed oxides exhibited 2.6 wt% hydrogen adsorption that were studied using temperature programmed reduction-adsorption-desorption (H2-TPR/TPD) and thermogravimetric and differential thermal analysis (TGA-DTA) techniques. Investigation corresponds that morphologies, textural properties and surface energy of mixed oxides are important in hydrogen adsorption.

scholarly journals Simultaneous Catalytic Oxidation of a Lean Mixture of CO-CH4 over Spinel Type Cobalt Based Oxides

2020 ◽  
Vol 15 (2) ◽  
pp. 490-500
Author(s):  
Neha Neha ◽  
Ram Prasad ◽  
Satya Vir Singh
Keyword(s):  
Mixed Oxides ◽  
Structural Disorder ◽  
Catalytic Performance ◽  
Molar Ratio ◽  
Total Oxidation ◽  
Spinel Type ◽  
Molar Ratios ◽  
Long Term Stability ◽  
Nickel Cobalt ◽  
Temperature Programmed

A series of nickel-cobalt bimetal oxides in varying molar ratios and its single metal oxides were synthesized by reactive calcination of coprecipitated basic-carbonates. Several characterization techniques, such as: Bruneuer Emmett Teller (BET), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infra Red (FTIR), and Hydrogen Temperature Programmed Reduction (H2-TPR), were performed over the oxides. Activities of oxides were evaluated in methane total oxidation in the presence or the absence of CO. The best catalytic performance was observed over NiCo catalyst with a Ni/Co molar ratio of 1:1, and the complete conversion of CO-CH4 mixture was achieved at 390 °C. Moreover, the presence of carbon monoxide improves CH4 total oxidation over nickel-cobalt mixed oxides. Structural analysis reveals that the insertion of nickel into the spinel lattice of cobalt oxide causes the structural disorder, which probably caused the increase of the amount of octahedrally coordinated divalent nickel cations that are responsible for catalytic activity. Stability of the best-performed catalyst has been tested in the two conditions, showing remarkable long-term stability and thermal stability, however, showed deactivation after thermally ageing at 700 °C. Copyright © 2020 BCREC Group. All rights reserved 

Doped lithium nickel cobalt mixed oxides for the positive electrode in lithium ion batteries

Ionics ◽  
2002 ◽  
Vol 8 (1-2) ◽  
pp. 92-99 ◽  
Author(s):  
C. Vogler ◽  
B. Löffler ◽  
W. Weirather ◽  
M. Wohlfahrt-Mehrens ◽  
J. Garche
Keyword(s):  
Lithium Ion Batteries ◽  
Mixed Oxides ◽  
Lithium Ion ◽  
Positive Electrode ◽  
Nickel Cobalt

Synthesis of Nano-Structured Ni-Co-Al Hydrotalcites and Derived Mixed Oxides

2012 ◽  
Vol 626 ◽  
pp. 173-177 ◽  
Author(s):  
M. Abdus Salam ◽  
Ye Lwin ◽  
Suriati Sufian
Keyword(s):  
Electron Microscopy ◽  
Mixed Oxides ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Pore Networks ◽  
Nickel Cobalt ◽  
Transmission Electron ◽  
Adsorption Desorption ◽  
Synthesized Materials ◽  
Fft Analysis

nanostructured hydrotalcite-like compounds that contain nickel, cobalt and aluminum have been synthesized by conventional coprecipitation method without using any surfactants or templating agents. The structure and morphology of the coprecipitated nanohydrotalcites and its derived mixed oxides were characterized by powder X-ray diffraction (XRD), Fourier-transformed Infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and nitrogen adsorption-desorption techniques. The results show that the synthesized materials exhibited micro-meso-pore networks. The cobalt-rich calcined hydrotalcites are generally amorphous, having a coral-like morphology whereas nickel-rich hydrotalcites show hexagonal plate-like morphology. The presence of nickel in mixed oxides catalyzed the reduction of Co-Al-O spinels. The Fast Fourier Transform (FFT) analysis of HRTEM revealed the inter planner distances of the crystal of hydrotalcite.

scholarly journals Mesoporous MnOx–CeO2 composites for NH3-SCR: the effect of preparation methods and a third dopant

RSC Advances ◽  
2019 ◽  
Vol 9 (21) ◽  
pp. 11912-11921 ◽  
Author(s):  
Li Weiman ◽  
Liu Haidi ◽  
Chen Yunfa
Keyword(s):  
Mixed Oxides ◽  
Preparation Methods ◽  
Nh3 Scr ◽  
Nickel Cobalt ◽  
Oxalate Route

In this study, an optimal oxalate route was used to obtain nickel/cobalt doped MnOx–CeO2 mixed oxides. Nickel doped MnOx–CeO2 showed excellent NH3-SCR activity and H2O + SO2 resistance.

Microstructure and reactivity of small metal particles: The role of Ce additives

1992 ◽  
Vol 50 (1) ◽  
pp. 318-319
Author(s):  
L.D. Schmidt ◽  
K. R. Krause ◽  
J. M. Schwartz ◽  
X. Chu
Keyword(s):  
Atmospheric Pressure ◽  
Noble Metals ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Chemical Shifts ◽  
Catalytic Converter ◽  
Structural Evolution ◽  
Single Particles ◽  
Small Metal Particles

The evolution of microstructures of 10- to 100-Å diameter particles of Rh and Pt on SiO2 and Al2O3 following treatment in reducing, oxidizing, and reacting conditions have been characterized by TEM. We are able to transfer particles repeatedly between microscope and a reactor furnace so that the structural evolution of single particles can be examined following treatments in gases at atmospheric pressure. We are especially interested in the role of Ce additives on noble metals such as Pt and Rh. These systems are crucial in the automotive catalytic converter, and rare earths can significantly modify catalytic properties in many reactions. In particular, we are concerned with the oxidation state of Ce and its role in formation of mixed oxides with metals or with the support. For this we employ EELS in TEM, a technique uniquely suited to detect chemical shifts with ∼30Å resolution.

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