The role of the WO3 nanostructures in the oxygen reduction reaction and PEM fuel cell performance on WO3–Pt/C electrocatalysts
The role of the WO3 nanostructures in the oxygen reduction reaction and PEM fuel cell performance on WO3–Pt/C electrocatalysts
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DOI：
10.1016/j.ijhydene.2015.06.165
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发表时间：
2015-12
影响因子：
7.2
通讯作者：
M. L. Hernández-Pichardo;R. González-Huerta;P. Angel;M. Tufiño-Velazquez;L. Lartundo
中科院分区：
文献类型：
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作者：
M. L. Hernández-Pichardo;R. González-Huerta;P. Angel;M. Tufiño-Velazquez;L. Lartundo
研究了化学还原法制备的碳负载氧化铂和氧化钨纳米颗粒的氧还原反应。结果与电催化剂的表面性质有关。采用x射线光电子能谱（XPS）、高分辨透射电子显微镜（HRTEM）、扫描透射电子显微镜（STEM）、能谱（EDS）等方法分析了WO3-Pt /C电催化剂的结构和表面性质。铂铂铂4f峰的XPS分析表明，该金属以pt0的形式存在于表面，并伴有部分氧化铂Pt2+，而氧化钨以W6+的形式存在。XPS结果表明，Pt与WO3之间存在较强的相互作用。通过电镜观察发现，采用该合成方法，铂和氧化钨都很好地分散在vulcan碳上，这可能有利于pt - wo3界面的形成。因此，与常规Pt/C相比，5%WO3-Pt /C电催化剂对单电池聚合物电解质膜（PEM）燃料电池中的氧还原反应表现出更高的电催化活性。然而，随着高含量氧化钨的掺入，氧化钨在催化剂表面占主导地位，降低了反应物对铂活性位点的可及性，从而降低了ORR中的电化学响应。
Oxygen reduction reaction (ORR) was investigated on carbon supported platinum and tungsten oxide nanoparticles generated by chemical reduction. The results were correlated with the surface properties of these electrocatalysts. X-ray Photoelectron Spectroscopy (XPS), High Resolution Transmission Electron Microscopy (HRTEM), Scanning Transmission Electron Microscopy (STEM), Energy Dispersive Spectroscopy (EDS) studies have been used to analyze the structure and surface properties of WO3–Pt/C electrocatalysts. The analysis of the platinum Pt 4f peak by XPS showed that this metal is present in the surface as Pt0with some oxidized platinum Pt2+, while tungsten oxide is present as W6+. The XPS results showed the strong interaction between Pt and WO3. By electron microscopy techniques, it was observed that using this synthesis method, both, platinum and tungsten oxide are well dispersed on vulcan carbon, which may favor the formation of Pt–WO3interfaces. Thus, in comparison to conventional Pt/C, the 5%WO3–Pt/C electrocatalyst exhibited higher electrocatalytic activity toward the oxygen reduction reaction in a single cell polymer electrolyte membrane (PEM) fuel cell. However, with the incorporation of tungsten oxide at higher contents the WOxspecies are more dominating on the catalysts surface, reducing the accessibility of the reactants to the platinum active sites and therefore the electrochemical response in the ORR.