Preparation and Characterization of Nanocomposite Calcium Doped Ceria Electrolyte With Alkali Carbonates (NK-CDC) for SOFC

2010 ◽  
Author(s):  
Ghazanfar Abbas ◽  
Rizwan Raza ◽  
Muhammad Ashraf Chaudhry ◽  
Bin Zhu
Keyword(s):  
Electron Microscopy ◽  
Fossil Fuels ◽  
Electrochemical Impedance ◽  
Renewable Energy Sources ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Doped Ceria ◽  
Alternative Source ◽  
Calcium Doped ◽  
Co Precipitation

The entire world’s challenge is to find out the renewable energy sources due to rapid depletion of fossil fuels because of their high consumption. Solid Oxide Fuel Cells (SOFCs) are believed to be the best alternative source which converts chemical energy into electricity without combustion. Nanostructured study is required to develop highly ionic conductive electrolyte for SOFCs. In this work, the calcium doped ceria (Ce0.8Ca0.2O1.9) coated with 20% molar ratio of two alkali carbonates (CDC-M: MCO3, where M = Na and K) electrolyte was prepared by co-precipitation method in this study. Ni based electrode was used to fabricate the cell by dry pressing technique. The crystal structure and surface morphology was characterized by X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM). The particle size was calculated in the range of 10–20nm by Scherrer’s formula and compared with SEM and TEM results. The ionic conductivity was measured by using AC Electrochemical Impedance Spectroscopy (EIS) method. The activation energy was also evaluated. The performance of the cell was measured 0.567W/cm2 at temperature 550°C with hydrogen as a fuel.

Preparation and Characterization of Nanocomposite Calcium Doped Ceria Electrolyte With Alkali Carbonates (NK-CDC) for SOFC

2011 ◽  
Vol 8 (4) ◽  
Author(s):  
Ghazanfar Abbas ◽  
Rizwan Raza ◽  
M. Ashraf Chaudhry ◽  
Bin Zhu
Keyword(s):  
Electron Microscopy ◽  
Fossil Fuels ◽  
Electrochemical Impedance ◽  
Renewable Energy Sources ◽  
Molar Ratio ◽  
Doped Ceria ◽  
Alternative Source ◽  
Dry Pressing ◽  
Calcium Doped ◽  
20 Nm

The entire world’s challenge is to find out the renewable energy sources due to rapid depletion of fossil fuels because of their high consumption. Solid oxide fuel cells (SOFCs) are believed to be the best alternative source, which converts chemical energy into electricity without combustion. Nanostructure study is required to develop highly ionic conductive electrolytes for SOFCs. In this work, the calcium doped ceria (Ce0.8Ca0.2O1.9) coated with 20% molar ratio of two alkali carbonates (CDC-M: MCO3, where M=Na and K) electrolyte was prepared by coprecipitation method. Ni based electrode was used to fabricate the cell by dry pressing technique. The crystal structure and surface morphology were characterized by an X-ray diffractometer, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (TEM). The particle size was calculated in the range 10–20 nm by Scherer’s formula and compared with SEM and TEM results. The ionic conductivity was measured by using ac electrochemical impedance spectroscopy method. The activation energy was also evaluated. The performance of the cell was measured 0.567 W/cm2 at temperature 550°C with hydrogen as a fuel.

Synthesis and Densification of Nanometric Ce0.8Sm0.2O1.9-δ

2006 ◽  
Vol 972 ◽  
Author(s):  
Vincenzo Esposito ◽  
Marco Fronzi ◽  
Enrico Traversa
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Electrochemical Impedance ◽  
Liquid Phase Sintering ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Conventional Sintering ◽  
Eis Measurements ◽  
Co Precipitation

AbstractNanometric 20% molar Sm-doped ceria (SDC20) powders were synthesized by tetrametylethylen ammine (TMDA) co-precipitation method. SDC20 was sintered in several conditions to control the final microstructure. Fast firing and conventional sintering were performed. LiNO3was used as an additive to promote liquid phase sintering of ceria at low temperatures (900-1200°C). Powders and dense pellets were analysed using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Electrochemical impedance spectroscopy (EIS) measurements were performed on dense pellets in air to estimate the contribution of grain boundary and bulk to the electrical conductivity. Liquid phase sintering produced the densest samples with the highest conductivity.

Chemical Synthesis of Nanostructured SrWO4 for Electrochemical Energy Storage and Conversion Applications

2014 ◽  
Vol 13 (02) ◽  
pp. 1450013 ◽  
Author(s):  
Hossein Farsi ◽  
Zahra Barzgari
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Impedance ◽  
Graphite Electrode ◽  
Catalyst Support ◽  
Reduction Reaction ◽  
Precipitation Method ◽  
Energy Storage And Conversion ◽  
Electron Microscopy Analysis ◽  
Eis Measurements ◽  
Co Precipitation

Nanostructured strontium tungstate was successfully synthesized by a co-precipitation method at 80°C. The structure and morphology of the obtained SrWO4 were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD pattern conformed that the prepared sample has a scheelite-type tetragonal structure. The electrochemical properties of the SrWO4 were investigated in 0.5 M NaOH electrolyte solution by cyclic voltammetry (CV), galvanostatic charge–discharge cycling and electrochemical impedance spectroscopy (EIS) measurements. Also, platinum have been supported onto the surface of SrWO4 /graphite electrode to use as catalyst support. The morphology of the catalysts was characterized by scanning electron microscopy analysis and EDX. The electrocatalytic activity of platinum loaded SrWO4 /graphite electrode toward oxygen reduction reaction (ORR) has been studied in 0.5 M H 2 SO 4 solution and compared with that of platinum supported on graphite using electrochemical measurements. The PtSrWO4 /graphite catalyst showed higher ORR activity than Pt /graphite catalyst.

scholarly journals Synthesis, Optical, Morphological and Magnetic Properties of Hematite Nanorods in Deep Eutectic Solvent with its Antibacterial and Photocatalytic Applications

2019 ◽  
Vol 31 (4) ◽  
pp. 879-885 ◽  
Author(s):  
Swathi Pon Sakthi Sri V. ◽  
A. Vijayakumar ◽  
Mary George
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Oxide Nanoparticles ◽  
Photocatalytic Activities ◽  
Co Precipitation

Deep eutectic solvent comprising of choline chloride and D(+)-glucose was synthesized by mixing in the molar ratio 2:1. Iron oxide nanoparticles were successfully synthesized by co-precipitation method. Deep eutectic solvent consisting of D(+)-glucose acts as a promising reducing agent for the synthesis of iron oxide nanoparticles. Direct optical band gap of iron oxide nanoparticles was found to be 2.262 eV. Powder X-ray diffraction technique was used to identify the crystalline phases. Surface morphology analysis by Field emission scanning electron microscopy and high resolution transmission electron microscopy confirmed the rod shape structure of the iron oxide nanoparticles. Selected area electron diffraction pattern revealed the identity of lattice planes with the XRD data. The antibacterial and photocatalytic activities of the iron oxide nanoparticles were also studied. The synthesized iron oxide nanoparticles showed appreciable antibacterial and photocatalytic activities

scholarly journals Electro-Oxidation of Ammonia at Novel Ag2O−PrO2/γ-Al2O3 Catalysts

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 257
Author(s):  
Mariam Khan ◽  
Naveed Kausar Janjua ◽  
Safia Khan ◽  
Ibrahim Qazi ◽  
Shafaqat Ali ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Impedance ◽  
Precipitation Method ◽  
Impregnation Method ◽  
X Rays ◽  
Kinetic And Thermodynamic Parameters ◽  
Catalytic Support ◽  
Transmission Electron ◽  
Electro Oxidation ◽  
Oxidation Of Ammonia

An Ag2O(x)−PrO2(y)/γ-Al2O3 electrocatalyst series (X:Y is for Ag:Pr from 0 to 10) was synthesized, to use synthesized samples in electrochemical applications, a step in fuel cells advancements. Ag2O(x)−PrO2(y)/γ-Al2O3/Glassy-Carbon was investigated for electrochemical oxidation of ammonia in alkaline medium and proved to be highly effective, having high potential utility, as compared to commonly used Pt-based electrocatalysts. In this study, gamma alumina as catalytic support was synthesized via precipitation method, and stoichiometric wt/wt.% compositions of Ag2O−PrO2 were loaded on γ-Al2O3 by co-impregnation method. The desired phase of γ-Al2O3 and supported nanocatalysts was obtained after heat treatment at 800 and 600 °C, respectively. The successful loadings of Ag2O−PrO2 nanocatalysts on surface of γ-Al2O3 was determined by X-rays diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR), and energy dispersive analysis (EDX). The nano-sized domain of the sample powders sustained with particle sizes was calculated via XRD and scanning electron microscopy (SEM). The surface morphology and elemental compositions were examined by SEM, transmission electron microscopy (TEM) and EDX. The conductive and electron-transferring nature was investigated by cyclic voltammetry and electrochemical impedance (EIS). Cyclic voltammetric profiles were observed, and respective kinetic and thermodynamic parameters were calculated, which showed that these synthesized materials are potential catalysts for ammonia electro-oxidation. Ag2O(6)−PrO2(4)/γ-Al2O3 proved to be the most proficient catalyst among all the members of the series, having greater diffusion coefficient, heterogeneous rate constant and lesser Gibbs free energy for this system. The catalytic activity of these electrocatalysts is revealed from electrochemical studies which reflected their potentiality as electrode material in direct ammonia fuel cell technology for energy production.

Effect of Fe and Co promoters on CO methanation activity of nickel catalyst prepared by impregnation – co-precipitation method

2020 ◽  
Vol 18 (5-6) ◽  
Author(s):  
Buyan-Ulzii Battulga ◽  
Tungalagtamir Bold ◽  
Enkhsaruul Byambajav
Keyword(s):  
Synergetic Effect ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Alumina Support ◽  
Co Methanation ◽  
Temperature Range ◽  
Co Precipitation ◽  
Catalyst Distribution

AbstractNi based catalysts supported on γ-Al2O3 that was unpromoted (Ni/γAl2O3) or promoted (Ni–Fe/γAl2O3, Ni–Co/γAl2O3, and Ni–Fe–Co/γAl2O3) were prepared using by the impregnation – co-precipitation method. Their catalytic performances for CO methanation were studied at 3 atm with a weight hourly space velocity (WHSV) of 3000 ml/g/h of syngas with a molar ratio of H2/CO = 3 and in the temperature range between 130 and 350 °C. All promoters could improve nickel distribution, and decreased its particle sizes. It was found that the Ni–Co/γAl2O3 catalyst showed the highest catalytic performance for CO methanation in a low temperature range (<250 °C). The temperatures for the 20% CO conversion over Ni–Co/γAl2O3, Ni–Fe/γAl2O3, Ni–Fe–Co/γAl2O3 and Ni/γAl2O3 catalysts were 205, 253, 263 and 270 °C, respectively. The improved catalyst distribution by the addition of cobalt promoter caused the formation of β type nickel species which had an appropriate interacting strength with alumina support in the Ni–Co/γAl2O3. Though an addition of iron promoter improved catalyst distribution, the methane selectivity was lowered due to acceleration of both CO methanation and WGS reaction with the Ni–Fe/γAl2O3. Moreover, it was found that there was no synergetic effect from the binary Fe–Co promotors in the Ni–Fe–Co/γAl2O3 on catalytic activity for CO methanation.

Nigeria: Advancing the Cause of Renewable Energy in Nigeria’s Power Sector Through its Legal Framework

2021 ◽  
Vol 50 (4-5) ◽  
pp. 433-444
Author(s):  
Olusola Joshua Olujobi ◽  
Temilola Olusola-Olujobi
Keyword(s):  
Renewable Energy ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Legal Framework ◽  
Comparative Approach ◽  
Energy Sources ◽  
Power Sector ◽  
Alternative Source ◽  
Regulatory Policies ◽  
Oil Sector

Fossil fuels have been the mainstream of energy supply and a major source of foreign exchange earnings for the Federal Government of Nigeria, in spite of being an unrenewable and unsustainable source of energy. Nigeria is yet to tap into the full benefits after privatising its power sector, including the new global evolution in the energy sector and the resulting increasing demand for renewable energy sources, which some consider to be cheaper and more environmentally friendly than fossil fuels and their allied products. Energy security is a challenge to socio-economic development in Nigeria, due to the country’s over-dependency on fossil fuels. In terms of their impact and the potentials to preserve energy sources for longevity and sustainability, however, fossil fuels will come to be seen as an out-dated alternative in the power sector as the energy industry evolves. The implications for Nigeria’s oil sector will not be limited to dwindling crude oil prices. The concerns include poor energy utilisation in Nigeria and the need to promote energy efficiency and sustainability. They have led to the formulation of new energy policies around the world to serve as a vehicle for translating solutions into reality. This study has adopted a library-based legal research method with a comparative approach. The study reveals that it is the lack of a coherent legal framework with incentives for using renewable energy that is largely seen as the key issue causing slow uptake of renewable energy as an alternative source of energy in Nigeria. As well as the need for a coherent legal framework on energy and incentives for using renewable energy sources, the study advocates stringent enforcement of existing energy regulatory policies.

Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

2018 ◽  
Vol 281 ◽  
pp. 40-45
Author(s):  
Jie Guang Song ◽  
Lin Chen ◽  
Cai Liang Pang ◽  
Jia Zhang ◽  
Xian Zhong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Hydrothermal Reaction ◽  
Synthesis Method ◽  
Particle Morphology ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Powder Materials ◽  
Co Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

Investigation on Synthesis Conditions of Silicon-Doped Hydrotalcite-Like Compounds

2013 ◽  
Vol 781-784 ◽  
pp. 239-242
Author(s):  
Lei Wang ◽  
Peng Xiao
Keyword(s):  
Silicon Content ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Accurate Data ◽  
Aged Condition ◽  
Synthesis Conditions ◽  
Silicon Doped ◽  
Major Factors ◽  
Co Precipitation ◽  
Research Analysis

In this paper, SiMgAl hydotalcite synthesis conditions were investigated using co-precipitation method, within a relatively stable pH environment of 8~9. Our research, analysis and discussion focused on the effects of major factors, such as material molar ratio ,silicon content and aged condition, on the structures of synthetic products. To achieve stable and accurate data, synthetic products were characterized by XRD and IR under the identical conditions. As shown in the results, it is suggested that the best Crystallization temperature is 70°C, molar ratio of Mg to Al is 3:1, and the best content of Silicon is 0.015mol/mol.

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