Microstructural refinement of Ni/Ce0.8Gd0.2O2−δ anodes for low-temperature solid oxide fuel cell by wet infiltration loading of PdCl2
| Autor: | Gyeong Man Choi, Sang Ho Oh, Ga-Young Shin, Amir Maghsoudipour, Mansoor Keyanpour-Rad, Fatemeh Sadat Torknik |
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| Rok vydání: | 2014 |
| Předmět: |
Materials science
Process Chemistry and Technology Non-blocking I/O Metallurgy chemistry.chemical_element Activation energy Redox Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Anode Adsorption Chemical engineering chemistry law Materials Chemistry Ceramics and Composites Calcination Solid oxide fuel cell Palladium |
| Zdroj: | Ceramics International. 40:12299-12312 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2014.04.075 |
| Popis: | Microstructural refinement of Ni/Gd 0.2 Ce 0.8 O 2− δ (Ni/GDC20) anode by wet-infiltration of PdCl 2 precursor was studied to further improve the anodic performance of low temperature solid oxide fuel cell (LT-SOFC). The effect of 2 oxidation reaction was examined using symmetric Ni–GDC20|GDC20|Pt electrolyte-supported cells at 400–600 °C. Nanostructure evolution before and after H 2 reduction at 600 °C and also after anodic performance test revealed effectiveness of PdO loading content on the nanoparticles architecture, with PdO as the sole Pd-phase after calcination at 600 °C with no residual chloride. In the process of H 2 reduction in high loading of PdO (0.26 mg/cm 2 ), a nano-grained network of metallic palladium (Pd 0 ) containing nanopores structure, which resulted from 40% volume deoxidizing shrinkage of PdO, was developed on the anode surface. But, in the case of small loading, PdH x phase indicating of H affinity of palladium and minute amounts of PdO on NiO were detected. The significant decrease of anodic polarization resistance, e.g. ~100 times at 500 °C, on highly Pd-infiltrated anode was accompanied with≤40 nm agglomerates in Pd-nanonetwork and 45% oxidizing of Pd 0 to PdO in H 2 environment. Detailed anodic impedance analysis and activation energy ( E a ) evaluation can be denoted to a balance between the E a of reaction-limiting step of charge transfer and the E a of the facilitating step of diffusion/adsorption/dissociation of the arrived O 2− species to triple phase boundaries (TPBs). Our findings verified that oxygen spillovering on the Pd 0 /PdO-pair nanocoating caused by the shift of the TPBs to the nanocoating-pair for H 2 oxidation reaction in LT-SOFC. |
| Databáze: | OpenAIRE |
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