Development of Plasma-Sprayed Molybdenum Carbide-Based Anode Layers with Various Metal Oxides for SOFC
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Air plasma-sprayed (APS) coatings provide an ability to deposit a range of novel fuel cell materials at competitive costs. This work develops three separate types of composite anodes (Mo-Mo2C/Al2O3, Mo-Mo2C/ZrO2, Mo-Mo2C/TiO2) using a combination of APS process parameters on Hastelloy®X for application in intermediate temperature proton-conducting solid oxide fuel cells. Commercially available carbide of molybdenum powder catalyst (Mo-Mo2C) and three metal oxides (Al2O3, ZrO2, TiO2) was used to prepare three separate composite feedstock powders to fabricate three different anodes. Each of the modified composition anode feedstock powders included a stoichiometric weight ratio of 0.8:0.2. The coatings were characterized by scanning electron microscopy, energy dispersive spectroscopy, x-ray diffraction, nanoindentation, and conductivity. We report herein that three optimized anode layers of thicknesses between 200 and 300 µm and porosity as high as 20% for Mo-Mo2C/Al2O3 (250-µm thick) and Mo-Mo2C/TiO2 (300 µm thick) and 17% for Mo-Mo2C/ZrO2 (220-µm thick), controllable by a selection of the APS process parameters with no addition of sacrificial pore-forming material. The nanohardness results indicate the upper layers of the coatings have higher values than the subsurface layers in coatings with some effect of the deposition on the substrate. Mo-Mo2C/ZrO2 shows high electrical conductivity.
Keywordsair plasma spray (APS) anode molybdenum carbide SOFC
This work has been supported by the project titled “Advance anode materials for direct hydrocarbon proton conducting solid oxide fuel cell (PC-SOFC) in auxiliary power unit,” funded by Saudi Aramco (Contract Number 6000074197).
- 1.Hydrogen & Fuel Cells: Review of National R&D Programs, International Energy Agency, Paris, 2004Google Scholar
- 10.Fuel Cells: Hydrocarbons Versus Hydrogen, Nature Asia, 2008Google Scholar
- 21.K.S. Weil, Analysis of the Structure and Magnetic Properties of New Multicomponent Transition Metal Nitride Compounds, The Electrochemical Society’s Interface, Winter, New York, 1998, p 49-51Google Scholar
- 25.S. Pirzada, T. Yadav, Integrated Thermal Process for the Continuous Synthesis of Nanoscale Powders, US Patent 5,851,507 A, 1998Google Scholar