In the face of environmental and energy problems, the new energy vehicle industry has been booming. The important component of electric vehicles different from traditional cars is their battery systems. Among them, fuel cells use hydrogen as raw material, and the product is water, which is a kind of pollution. An ideal battery system with low energy conversion efficiency. However, in the face of large-scale commercialization, fuel cells also have greater resistance in terms of cost. The main performance is that the battery cathode requires a large amount of precious metal platinum-based catalyst. Platinum-based materials are expensive. The limited reserves have greatly hindered the sustainability of fuel cells and large-scale application. Therefore, it is urgent to prepare a new type of cathode catalyst with excellent performance, low price and abundant reserves to replace platinum-based catalysts.
In response to the above problems, under the guidance of Li Yuliang, an academician of the Chinese Academy of Sciences, Huang Changshui, a researcher at the Qingdao Institute of Bioenergy and Process, Chinese Academy of Sciences, led a carbon-based materials and energy application research group to design a new graphene-alkyne group in which a part of carbon atoms in a benzene ring are connected to hydrogen. Carbon material (HsGDY) catalyst. The design and implementation of this material was based on the successful synthesis and application of a large number of graphene-based materials in the early stage of the research group. The relevant results have been published in the international journal Nature Communications, 2018. , 9, 3376), and was selected as Highlight work.
Thanks to the unique structure of HsGDY, in the post-treatment process, the carbon-based materials and energy application research group accurately controlled the nitrogen incorporation type, and selectively incorporated the most effective pyridinium nitrogen atom for the fuel cell cathode electrocatalysis. In order to achieve excellent catalytic performance, HsGDY has hexagonal macropores with a molecular pore size of 1.63 nm, which is beneficial to the mass transfer of reactants and products during the catalytic reaction. It is found by electrochemical test that pyridine nitrogen is mixed. The heterogeneous HsGDY exhibits superior activity over commercial carbon-supported platinum catalysts under alkaline conditions. Its current density at a potential of 0.85 V is 1.6 times that of a commercial carbon-supported platinum catalyst, and it is better than platinum on carbon. Stability and resistance to methanol poisoning. Pyridinium-doped HsGDY as a new fuel cell cathode catalyst replaces traditional platinum-based catalysts, showing great potential. This method of carbon nanotube structure design to achieve accurate doping of heteroatoms It also provides a new idea for the preparation of other doped nanomaterials.
The research was supported by the National Natural Science Foundation of China, the key project of the Chinese Academy of Sciences, and the Natural Science Foundation of Shandong Province.
Figure: Electrochemical properties and reaction process of pyridinium-doped graphene materials
