石墨烯负载纳米Co基催化剂的可控制备与催化性能

Owing to its novel and unique physical and chemical properties, the graphene based material has been attracting more and more attention from scientific. The nanocomposites exhibit excellent properties and improved functionalities due to the synergetic effects between graphene and the components, thus have been widely used in the fields of catalysis, energy, analytical, biotechnology and pollutants removal applications. However, little is known about synergetic coupling effects between the components and graphene. The project will controllable synthesis cobalt-based nanocrystals grown on graphene as a catalyst for CO oxidation reaction. We will investigate the effects of the coverage, morphology, surface structure on the CO oxidation activity. The first-principles theoretical calculation combined with other experimental methods could be carried out to analyze the electron transfer and the synergetic catalytic effects between grahpene and cobalt-based nanostructures. Relationships between the electronic structure and the catalytic reaction are investigated to understand the role of surface effects, quantum effects, interface effects on catalysis. These results should be helpful in promoting the development of catalytic theory and providing theoretical and experimental basis for the large-scale application of graphene-based materials in catalysis.

石墨烯材料具有很多优异的物理和化学性能，是纳米材料领域的一大研究热点。石墨烯基纳米材料不但可以同时保持石墨烯和纳米粒子的固有特性，而且能够产生新颖的协同效应，在传感器、储氢材料、电极材料和催化等领域具有广阔的应用前景。但石墨烯与纳米粒子间的协同催化机理仍不清楚。本项目将通过石墨烯负载钴基纳米材料的可控制备，选择汽车尾气CO的催化氧化反应为模型反应，检验催化剂的活性。研究纳米粒子覆盖度、形貌和表面结构对催化剂性能的影响。采用第一性原理理论计算结合其他实验手段，分析石墨烯与纳米粒子间的电子传递及协同催化机制。研究催化剂的电子性质与催化反应的关系，认识表面效应、量子效应、界面效应对催化的作用。促进催化理论的发展，为实现石墨烯基纳米材料在催化方面的大规模应用提供理论与实验依据。

由于其独特的结构和电子学性质，石墨烯是当前新材料研究中最为活跃的领域之一。石墨烯的改性，对于实现各种实际应用至关重要。原子掺杂是调制石墨烯性质的有效方式之一。我们发现，通过化学气相沉积（CVD）法在适当的生长条件下，石墨烯的掺杂类型可以由N单质来进行调整，吡啶N和石墨N优先分布在不同的域中，这将使石墨烯片中的功能结构的生长更加方便。另一方面，不同的N结构对应于不同的功能，而一些重要应用趋向与主要的N结构，并且目前几乎没有办法制备只有一种同类型的N键合构型的N掺杂石墨烯。采用氮离子溅射的方法，我们在碳化硅表面单步制备了氮掺杂石墨烯。通过控制生长参数，可以调制石墨烯中N原子掺杂的键合构型，可控的生长纯pyridinic-N氮掺杂石墨烯样品，这一发现将促进氮掺杂石墨烯在催化领域的应用。由于本人初次主持项目，在项目执行过程中也出现一些偏差，在今后的工作中将加以改正。