Factors for improvements of catalytic activity for zirconium oxide-based oxygen-reduction electrocatalysts
Factors for improvements of catalytic activity for zirconium oxide-based oxygen-reduction electrocatalysts
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氧化锆基氧还原电催化剂催化活性提高的因素
DOI：
10.1149/1.3635655
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
H.Imai
中科院分区：
文献类型：
--
作者：
Y.Ohgi;A.Ishihara;K.Matsuzawa;S.Mitsushima;K.Ota;M.Matsumoto;H.Imai
氧化锆基催化剂被评为聚合物电解质燃料电池的非贵金属阴极。样品是由碳氮化锆在1000oC下，在10-2到10-22atm的控制氧分压下制备的。高分辨X射线衍射仪的Rietveld分析表明，在比质量分数附近，晶格参数和Zr和O的占有率显著降低，表明在单斜晶系中形成了氧空位。从X射线衍射仪、XPS、TOF-SIMS分析推测，氧化物的形成可能与表面和体相的氧空位等缺陷有关。此外，缺陷浓度较高的氧化物的形成可能是由于碳在表面的行为引起的。氧空位可能是ORR的活性中心，增加氧空位是提高Zr-CNOS中ORR催化活性的因素之一。
Zirconium oxide based catalysts were evaluated as a non-precious cathode for polymer electrolyte fuel cells. Samples were prepared from zirconium carbonitrides under controlled oxygen partial pressure from 10-2 to 10-22 atm at 1000oC. Significant decrease in lattice parameter and Zr and O occupancy at around specific mass fraction revealed from high resolution XRD with Rietveld analysis, indicating formation of oxygen vacancies in monoclinic ZrO2. It is extrapolated from XRD, XPS, TOF-SIMS analyses that the oxide might be formed with the defects such as oxygen vacancy at both surface and bulk. Additionally, formation of the oxide with high concentration of the defects might be caused by behavior of the carbon on the surface. The oxygen vacancies could be active sites for the ORR, and increasing such oxygen-vacancy sites is one of the factors to improve the catalytic activity for the ORR in Zr-CNOs.