纳米碳纤维的微观结构调控与催化作用

纳米碳纤维（CNF）是一种新型一维结构纳米炭材料，因其具有许多独特的性质而备受研究者关注。按照CNF基本结构单元石墨片层与生长轴的夹角不同，可以将CNF分为板式、鱼骨式和管式3种不同微观结构。采用催化化学气相沉积法合成CNF时，微观结构可以通过改变生长动力学进行调控。CNF微观结构的不同导致表面棱边与基面原子比例不同，进而影响着表面含氧基团分布等性质。当CNF用作催化剂载体时，利用这些性质的不同可以调控负载金属颗粒的形貌以及载体与金属作用力等性质，从而改变催化剂的性能。CNF自身具有催化活性，其活性主要来自表面杂原子基团，因此也与CNF的微观结构密切相关。

Manipulating microstructural properties of carbon nanofibers and their applications in catalysis

As a new category of carbonaceous material, carbon nanofiber (CNF) has been extensively studied due to its unique characteristics. CNF is usually classified according to the angle between fiber axis and graphene sheets, that is, platelet, fishbone and tubular CNF. CNF with different microstructures could be synthesized by adjusting the preparation methods. For catalytic chemical vapor deposition method, the structural properties of the as-synthesized CNF are kinetically controlled. The differences of the structure properties of CNF with different microstructures would lead to different ratios of edge/basal atoms and consequently distributions of surface oxygen complex, wettability and other properties. When using CNF as catalyst support, morphologies, particle size distribution, interaction between the CNF support and metal particles and crystal plane orientation could be manipulated, leading to different catalytic performance. CNF has its own catalytic activities as verified by oxidative dehydrogenation of alkanes as solid base catalyst. The activities originate from the existence of heteroatoms on CNF surface, e.g., surface oxygen complexes and doped N. Since the chemistry of CNF surface depends on its microstructure, the great influence of structure properties on their catalytic performance has been evidenced in many researches. CNF with macroscopic shaping could be prepared through several methods. The characteristics of fluid dynamics of a CNF/graphite felt is also reviewed.