| 1. |
- Farhan, Shumail, et al.
(författare)
-
Co-doped cerium oxide Fe0.25xMnxCe0.75O2-delta as a composite cathode material for IT-SOFC
- 2022
-
Ingår i: Journal of Alloys and Compounds. - Amsterdam, Netherlands : Elsevier. - 0925-8388 .- 1873-4669. ; 906
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, Fe-Mn co-doped ceria Fe0.25Mn0.00Ce0.75O2-delta (FMDC1), Fe0.23Mn0.02Ce0.75O2-δ (FMDC2), Fe0.21Mn0.04Ce0.75O2-δ (FMDC3), and Fe0.19Mn0.06Ce0.75O2-δ (FMDC4) powders are synthesized by sol gel method and evaluated as cathode materials for intermediate temperature solid oxide fuel cell (IT-SOFC). The combination of Fe and Mn significantly enhanced the ceria catalytic activity and oxygen kinetics for redox-based reactions. The effects of the co-doping mechanism on the phase composition, optical behavior, and electrochemical performance are mainly investigated. The prepared samples are characterized by XRD, SEM, FTIR, UV-vis, and conductivity tests. X-ray diffraction analysis revealed well-developed crystallinity with a single phase cubic structure of synthesized cathode material. SEM depicted the highly porous facet for Fe0.19Mn0.06Ce0.75O2-δ (FMDC4) resulted in the large triple-phase boundaries for the reduction of ambient air. The inclusion of Mn3+ and Fe3+ ions into CeO2 network created additional oxygen vacancies (Ov) and simultaneously reduced the optical band gap energy from 2.81 eV for FMDC1 (x = 0.00) to 2.54 eV for FMDC4 (x = 0.06). Among the four samples, FMDC4 possessed the highest electrical conductivity (∼0.89 Scm-1) at 650 degrees C and corresponding low activation energy of similar to 0.301 eV, which lead to good catalytic activity with an enhanced electrochemical performance of the SOFC system. The open-circuit voltage (OCV) attained the value of ∼0.98 V, maximum power density of ∼335 mW cm-2 is obtained at 550 degrees C, which is comparable to previously reported electrodes. The results suggested that the combination of Fe and Mn into ceria can be used as an effective catalytic promoter for oxygen reduction reactions (ORR), and the composition of FMDC4 resulted in the peak conductivity, short term stability and highest power density as compared to other synthesized samples. (C) 2022 The Authors. Published by Elsevier B.V.
|
|
| 2. |
- Sarfraz, Amina, et al.
(författare)
-
Catalytic Effect of Silicon Carbide on the Composite Anode of Fuel Cells
- 2021
-
Ingår i: ACS Applied Energy Materials. - : AMER CHEMICAL SOC. - 2574-0962. ; 4:7, s. 6436-6444
-
Tidskriftsartikel (refereegranskat)abstract
- High efficiency, fuel flexibility, and sustainable energy conversion make fuel cells attractive compared to conventional energy systems. The direct ethanol fuel cells have attracted much attention because of the direct utilization of ethanol fuel. Anode materials are required to enhance the catalytic activity of the liquid fuel, which oxidize the fuel at lower operating temperature. Therefore, the catalytic effect using silicon carbide has been investigated in the LiNiO2-delta anode. The material has been characterized, and it is found that SiC shows a cubic structure and LiNiO2-delta exhibits a hexagonal structure, while the LiNiO2-delta-SiC composite exhibits a mixed cubic and hexagonal phase. Scanning electron microscopy depicts that the material is porous. The Fourier transform infrared spectroscopy analysis shows the presence of Si-O-Si, Si-C, C=O, and Si-OH bonding. The LiNiO2-delta-SiC composite (1:0.3) exhibited a maximum electrical conductivity of 1.34 S cm(-1) at 650 degrees C with an electrical band gap of 0.84 eV. The fabricated cell with the LiNiO2-delta-SiC anode exhibits a power density of 0.20 W cm(-2) at 650 degrees C with liquid ethanol fuel. The results show that there is a promising catalytic activity of SiC in the fuel cell anode.
|
|
| 3. |
- Zheng, Xiaoxiao, et al.
(författare)
-
Graphene-Oxide-Based Fluoro- and Chromo-Genic Materials and Their Applications
- 2022
-
Ingår i: Molecules. - : MDPI AG. - 1431-5157 .- 1420-3049. ; 27:6
-
Tidskriftsartikel (refereegranskat)abstract
- Composite materials and their applications constitute a hot field of research nowadays due to the fact that they comprise a combination of the unique properties of each component of which they consist. Very often, they exhibit better performance and properties compared to their combined building blocks. Graphene oxide (GO), as the most widely used derivative of graphene, has attracted widespread attention because of its excellent properties. Abundant oxygen-containing functional groups on GO can provide various reactive sites for chemical modification or functionalization of GO, which in turn can be used to develop novel GO-based composites. This review outlines the most recent advances in the field of novel dyes and pigments encompassing GO as a key ingredient or as an important cofactor. The interactions of graphene with other materials/compounds are highlighted. The special structure and unique properties of GO have a great effect on the performance of fabricated hybrid dyes and pigments by enhancing the color performance of dyes, the anticorrosion properties of pigments, the viscosity and rheology of inks, etc., which further expands the applications of dyes and pigments in dyeing, optical elements, solar-thermal energy storage, sensing, coatings, and microelectronics devices. Finally, challenges in the current development as well as the future prospects of GO-based dyes and pigments are also discussed. This review provides a reference for the further exploration of novel dyes and pigments.
|
|
| 4. |
- Abbas, Ghazanfar, et al.
(författare)
-
Electrochemical investigation of mixed metal oxide nanocomposite electrode for low temperature solid oxide fuel cell
- 2017
-
Ingår i: International Journal of Modern Physics B. - : WORLD SCIENTIFIC PUBL CO PTE LTD. - 0217-9792. ; 31:27
-
Tidskriftsartikel (refereegranskat)abstract
- Zinc-based nanostructured nickel (Ni) free metal oxide electrode material Zn-0.60/CU0.20Mn0.20 oxide (CMZO) was synthesized by solid state reaction and investigated for low temperature solid oxide fuel cell (LTSOFC) applications. The crystal structure and surface morphology of the synthesized electrode material were examined by XRD and SEM techniques respectively. The particle size of ZnO phase estimated by Scherer's equation was 31.50 nm. The maximum electrical conductivity was found to be 12.567 S/cm and 5.846 S/cm in hydrogen and air atmosphere, respectively at 600 degrees C. The activation energy of the CMZO material was also calculated from the DC conductivity data using Arrhenius plots and it was found to be 0.060 and 0.075 eV in hydrogen and air atmosphere, respectively. The CMZO electrode-based fuel cell was tested using carbonated samarium doped ceria composite (NSDC) electrolyte. The three layers 13 mm in diameter and 1 mm thickness of the symmetric fuel cell were fabricated by dry pressing. The maximum power density of 728.86 mW/cm(2) was measured at 550 degrees C.
|
|
| 5. |
- Abbas, Ghazanfar, et al.
(författare)
-
Electrochemical study of nanostructured electrode for low-temperature solid oxide fuel cell (LTSOFC)
- 2014
-
Ingår i: International Journal of Energy Research. - : Hindawi Limited. - 0363-907X .- 1099-114X. ; 38:4, s. 518-523
-
Tidskriftsartikel (refereegranskat)abstract
- Zn-based nanostructured Ba0.05Cu0.25Fe0.10Zn0.60O (BCFZ) oxide electrode material was synthesized by solid-state reaction for low-temperature solid oxide fuel cell. The cell was fabricated by sandwiching NK-CDC electrolyte between BCFZ electrodes by dry press technique, and its performance was assessed. The maximum power density of 741.87 mW-cm(-2) was achieved at 550 degrees C. The crystal structure and morphology were characterized by X-ray diffractometer (XRD) and SEM. The particle size was calculated to be 25 nm applying Scherer's formula from XRD data. Electronic conductivities were measured with the four-probe DC method under hydrogen and air atmosphere. AC Electrochemical Impedance Spectroscopy of the BCFZ oxide electrode was also measured in hydrogen atmosphere at 450 degrees C.
|
|
| 6. |
- Abbas, Ghazanfar, et al.
(författare)
-
Preparation and characterization of nanocomposite calcium doped ceria electrolyte with alkali carbonates (NK-CDC) for SOFC
- 2010
-
Ingår i: ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology, FUELCELL 2010. - : ASME Press. - 9780791844052 ; , s. 427-432
-
Konferensbidrag (refereegranskat)abstract
- 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 (Ce0.8Ca0.2O 1.9) 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.
|
|
| 7. |
- Abbas, Ghazanfar, et al.
(författare)
-
Preparation and Characterization of Nanocomposite Calcium Doped Ceria Electrolyte With Alkali Carbonates (NK-CDC) for SOFC
- 2011
-
Ingår i: Journal of Fuel Cell Science and Technology. - : ASME International. - 1550-624X .- 1551-6989. ; 8:4, s. 041013-
-
Tidskriftsartikel (refereegranskat)abstract
- 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/cm(2) at temperature 550 degrees C with hydrogen as a fuel.
|
|
| 8. |
- Abbas, Ghazanfar, et al.
(författare)
-
Study of CuNiZnGdCe-Nanocomposite Anode for Low Temperature SOFC
- 2012
-
Ingår i: Nanoscience and Nanotechnology Letters. - : American Scientific Publishers. - 1941-4900 .- 1941-4919. ; 4:4, s. 389-393
-
Tidskriftsartikel (refereegranskat)abstract
- Composite electrodes of Cu0.16Ni0.27Zn0.37Ce0.16Gd0.04 (CNZGC) oxides have been successfully synthesized by solid state reaction method as anode material for low temperature solid oxide fuel cell (LTSOFC). These electrodes are characterized by XRD followed by sintering at various time periods and temperatures. Particle size of optimized composition was calculated 40-85 nm and sintered at 800 degrees C for 4 hours. Electrical conductivity of 4.14 S/cm was obtained at a temperature of 550 degrees C by the 4-prob DC method. The activation energy was calculated 4 x 10(-2) eV at 550 degrees C. Hydrogen was used as fuel and air as oxidant at anode and cathode sides respectively. I-V/I-P curves were obtained in the temperature range of 400-550 degrees C. The maximum power density was achieved for 570 mW/cm(2) at 550 degrees C.
|
|
| 9. |
- Abbas, Ghazanfar, et al.
(författare)
-
Synthesize and characterization of nanocomposite anodes for low temperature solid oxide fuel cell
- 2015
-
Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 40:1, s. 891-897
-
Tidskriftsartikel (refereegranskat)abstract
- Solid oxide fuel cells have much capability to become an economical alternative energy conversion technology having appropriate materials that can be operated at comparatively low temperature in the range of 400-600 degrees C. The nano-scale engineering has been incorporated to improve the catalytic activity of anode materials for solid oxide fuel cells. Nanostructured Al0.10NixZn0.90-xO oxides were prepared by solid state reaction, which were then mixed with the prepared Gadolinium doped Ceria GDC electrolyte. The crystal structure and surface morphology were characterized by XRD and SEM. The particle size was evaluated by XRD data and found in the range of 20-50 nm, which was then ensured by SEM pictures. The pellets of 13 mm diameter were pressed by dry press technique and electrical conductivities (DC and AC) were determined by four probe techniques and the values have been found to be 10.84 and 4.88 S/cm, respectively at hydrogen atmosphere in the temperature range of 300-600 degrees C. The Electrochemical Impedance Spectroscopy (EIS) analysis exhibits the pure electronic behavior at hydrogen atmosphere. The maximum power density of ANZ-GDC composite anode based solid oxide fuel cell has been achieved 705 mW/cm(2) at 550 degrees C.
|
|
| 10. |
- Afroz, Laila, et al.
(författare)
-
Nanocomposite Catalyst (1 – x)NiO-xCuO/yGDC for Biogas Fueled Solid Oxide Fuel Cells
- 2023
-
Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 6:21, s. 10918-10928
-
Tidskriftsartikel (refereegranskat)abstract
- The composites of Ni–Cu oxides with gadolinium doped ceria (GDC) are emerging as highly proficient anode catalysts, owing to their remarkable performance for solid oxide fuel cells operated with biogas. In this context, the nanocomposite catalysts (1 – x)NiO-xCuO/yGDC (x = 0.2–0.8; y = 1,1.3) are synthesized using a solid-state reaction route. The cubic and monoclinic structures are observed for NiO and CuO phases, respectively, while CeO2 showed cubic fluorite structure. The scanning electron microscopic images revealed a rise in the particle size with an increase in the copper and GDC concentration. The optical band gap values are calculated in the range 2.82–2.33 eV from UV–visible analysis. The Raman spectra confirmed the presence of vibration modes of CeO2 and NiO. The electrical conductivity of the nanocomposite anodes is increased as the concentration of copper and GDC increased and reached at 9.48 S cm–1 for 0.2NiO-0.8CuO/1.3GDC composition at 650 °C. The electrochemical performance of (1 – x)NiO-xCuO/yGDC (x = 0.2–0.8; y = 1,1.3)-based fuel cells is investigated with biogas fuel at 650 °C. Among all of the as-synthesized anodes, the fuel cell with composition 0.2NiO-0.8CuO/1.3GDC showed the best performance, such as an open circuit voltage of 0.84 V and peak power density of 72 mW cm–2. However, from these findings, it can be inferred that among all other compositions, the 0.2NiO-0.8CuO/1.3GDC anode is a superior combination for the high electrochemical performance of solid oxide fuel cells fueled with biogas.
|
|
