原位掺杂石墨烯量子点氧还原催化协同作用机理及性能研究

Nowadays there are some problems (i.e. stability, cost, catalytic selectivity) of cathode oxygen reduction reaction(ORR) electrocatalyst Pt/C of the fuel cells, many researchers have taken the extensive consideration into the development of new non-noble metal electrocatalysts for oxygen reduction. In this project, we attempt to synthesize graphene quantum dots (GQDs)by some methods such as frequency conversioncyclic voltammetry etching of carbon fiber, the GQDs will be in-situ doped with heteroatom such as nitrogen, boron, sulfur, phosphorus, fluorine or in combinations. Then the heteroatom-doped GQDs(named X-GQDs) and metal carbide(i.e. WC ) will be combined into nanocomposites(named MC@X-GQDs) to be the electrocatalysts for the ORR. The electrocatalytic, physical and chemical performance of samples would be tested and characterized. We would investigate to the controllable synthesis of GQDs, X-GQDs and MC@X-GQDs,the effects of heteroatom-doped and MC for the structure and catalytic properties of GQDs. The electrocatalysis enhanced mechanism of X-GQDs would be also carried out. We attempt to provide technical and theoretical support for the controllable synthesis of X-GQDs and the development of the new noble-metal free ORR electrocatalysts with low-cost and high-performance.

燃料电池铂碳氧还原催化材料存在成本、稳定性、催化选择性等瓶颈问题，发展新型非贵金属氧还原催化剂引起了广泛的研究兴趣。本项目拟用变频循环伏安刻蚀碳纤维等方法可控制备石墨烯量子点，并对其进行氮、硼、硫、磷、氟等杂原子原位掺杂或共掺杂，结合过渡金属碳化物合成纳米复合物作为非贵金属氧还原催化材料。通过电催化与物化性能测试、表征，研究原位掺杂石墨烯量子点的可控制备、杂原子掺杂及金属碳化物对石墨烯量子点结构和催化性能的影响，探索掺杂石墨烯量子点与碳化物协同催化增强机理，为可控合成低成本高性能新型石墨烯量子点基氧还原催化材料的开发提供技术支持和理论依据。

氧还原催化材料存在成本、稳定性、催化选择性等瓶颈问题，发展新型石墨烯基非贵金属氧还原催化剂意义重大。本项目采用刻蚀碳纤维等方法可控制备石墨烯量子点，并对其进行氮、氟等杂原子原位掺杂，合成纳米复合物作为非贵金属氧还原催化材料。通过电催化与物化性能测试、表征，研究原位掺杂石墨烯量子点的可控制备、杂原子掺杂及金属碳化物对石墨烯量子点结构和催化性能的影响，探索掺杂石墨烯量子点与碳化物协同催化增强机理。本项目采用一步溶剂热法合成四氧化三钴与氮掺杂石墨烯量子点纳米复合物（Co3O4@N-GQDs）。在0.1M KOH碱性条件下的半波电位和极限电流密度分别为0.77 V、5.48 mA cm-2 ，经过2500圈循环后，半波电位衰减0.7%，催化活性和稳定性优异。本项目的研究为可控合成低成本高性能新型石墨烯量子点基氧还原催化材料的开发提供技术支持和理论依据。