Spherical Core–Shell Titanium (Oxy)nitride@Nitrided Carbon Composites as Catalysts for the Oxygen Reduction Reaction: Synthesis and Electrocatalytic Performance
Spherical Core–Shell Titanium (Oxy)nitride@Nitrided Carbon Composites as Catalysts for the Oxygen Reduction Reaction: Synthesis and Electrocatalytic Performance
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DOI：
10.1002/celc.201600246
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发表时间：
2016-10
期刊：
影响因子：
6.1
通讯作者：
M. Wassner;M. Eckardt;C. Gebauer;N. Hüsing;R. Behm
中科院分区：
文献类型：
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作者：
M. Wassner;M. Eckardt;C. Gebauer;N. Hüsing;R. Behm
为了开发用于聚合物电解质燃料电池（PEFC）中的氧还原反应（ORR）的高活性和稳定的无铂催化剂，我们探索了一种新型复合材料的潜力，其中核-壳结构应导致高ORR活性和改善的导电性的组合。以葡萄糖为原料，通过水热法合成了粒径约300 nm的碳球，并采用溶胶-凝胶法制备了均匀的二氧化钛壳层，制备了TiOxNy@CnNm复合纳米粒子。然后使核-壳颗粒在氨蒸气中在不同温度（550 °C-150 °C）下进行氮化。氮化温度对所得复合颗粒的结构和相组成的影响通过多种技术进行评估，包括电子显微镜（SEM、TEM）、X射线衍射（XRD）、X射线光电子能谱（XPS）、元素分析、热重（TG）分析和N2吸附测量，通过旋转环盘电极（RRDE）测量确定材料的电化学性质和ORR性能。的结构/化学性质和电化学/电催化性能的演变趋势，以及它们之间的相关性进行了讨论;优化的介孔的钛（氧）氮化物壳被确定为催化剂的ORR性能的关键标准。
Aiming at the development of highly active and stable platinum-free catalysts for the oxygen reduction reaction (ORR) in polymer electrolyte fuel cells (PEFCs), we explored the potential of a new composite material, where the core–shell structure should result in a combination of high ORR activity and improved electric conductivity. TiOxNy@CnNm composite nanoparticles were prepared by covering uniform carbon spheres of about 300 nm in size, synthesized through the hydrothermal reaction of glucose, with a homogeneous titania shell made by sol-gel processing. The core–shell particles were then subjected to nitridation in ammonia vapor at different temperatures (550 °C–150 °C). The influence of the nitridation temperature on the structure and phase composition of the resulting composite particles was evaluated by a variety of techniques, including electron microscopy (SEM, TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), elemental analysis, thermogravimetric (TG) analysis, and N2 sorption measurements, the electrochemical properties and the ORR performance of the materials were determined by rotating ring disk electrode (RRDE) measurements. Trends in the evolution of the structural/chemical properties and electrochemical/electrocatalytic properties as well as correlations between them are discussed; an optimized mesoporosity of the titanium (oxy)nitride shell was identified as the key criterion for the catalyst's ORR performance.