Electrocatalysis on Shape-Controlled Titanium Nitride Nanocrystals for the Oxygen Reduction Reaction
Electrocatalysis on Shape-Controlled Titanium Nitride Nanocrystals for the Oxygen Reduction Reaction
复制标题
形状控制氮化钛纳米晶电催化氧还原反应
DOI：
10.1002/cssc.201300331
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发表时间：
2013-10-01
期刊：
影响因子：
8.4
通讯作者：
Li, Jinghong
中科院分区：
文献类型：
--
作者：
Dong, Youzhen;Wu, Yongmin;Li, Jinghong
用于氧还原反应（ORR）的铂（Pt）基阴极催化剂的高价格已经减缓了燃料电池的实际应用。氮化钛（TiN）具有低成本、优异的催化性能和稳定性，是最有希望取代铂的非贵金属电催化剂之一。然而，TiN电催化剂的形状-活性关系至今尚未得到很好的研究或理解。在这项工作中，通过简单地调整TiO 2前体的形状，我们能够定制的TiN催化剂从纳米颗粒到纳米管的形态。我们已经合成了均匀的碳包覆氮化钛纳米管（碳包覆TiN NTs），通过氮化反应，在NH3流使用TiO 2纳米管/三聚氰胺混合物作为前体。碳包覆的TiN NT杂化物通过有效的四电子主导的ORR过程表现出优异的ORR电催化活性，与商业Pt/C相比，具有上级甲醇耐受性和长期稳定性。与纳米粒子相比，碳纳米管的一维中空结构使电解质在纳米粒子表面的扩散更大，导电性更上级，从而大大提高了碳包覆TiN纳米管复合材料的电催化性能。
The high price of platinum (Pt)-based cathode catalysts for the oxygen reduction reaction (ORR) have slowed down the practical application of fuel cells. Thanks to their low cost, and outstanding, stable catalytic properties, titanium nitrides (TiN) are among the most promising non-precious metal electrocatalysts for replacing Pt. However, the shape-activity relationships of TiN electrocatalysts have not been well-studied or understood up to now. In this work, by simply adjusting the shape of TiO2 precursor, we are able to tailor the morphology of the TiN catalysts from nanoparticles to nanotubes. We have synthetized uniform carbon-coated titanium nitride nanotubes (carbon-coated TiN NTs) through a nitridation reaction in NH3 flow using a TiO2 nanotubes/melamine mixture as precursor. The carbon-coated TiN NTs hybrids exhibit excellent electrocatalytic activity for the ORR, coupled with superior methanol tolerance and long-term stability in comparison to commercial Pt/C, through an efficient four-electron-dominant ORR process. Compared with nanoparticles, the one-dimensional and hollow structure of the nanotubes result in greater diffusion of electrolyte and superior electrical conductivity, and contribute to the greatly improved electrocatalytic performance of the carbon-coated TiN NTs nanocomposites.