Mental Organic Frameworks Derived Carbon Cataltsts For Oxygen Reduction Reaction

Proton exchange membrane fuel cells(PEMFC)have been widely studied for their low cost,environmental friendliness and high energy density.However,the slow kinetics of the oxygen reduction reaction(ORR)has seriously hindered their development,so it is crucial to develop efficient ORR electrocatalysts.This paper introduces the basic structure and development status of proton exchange membrane fuel cells,the reaction principle of cathode oxygen reduction and common cathode catalysts,and explores the preparation process of non-precious metal catalyst Ru-N-C and composite catalyst Pt/Ru-N-C to reveal the principle of catalyst performance enhancement.Ru-N-C catalysts were prepared by stirring at room temperature,and the effects of different Zn,Ru ratios in the precursors,different carbonization temperatures and carbonization times on the performance of Ru-N-C catalysts were systematically investigated.A series of characterization methods were used to compare the performance of Ru-N-C catalysts prepared under different preparation processes,and it was found that the best performance was achieved when the precursor was Zn/Ru=30:1,the carbonization temperature was 950 ℃,and the carbonization time was 1 h.The catalysts had more microporous structures and mesoporous structures,which increased the specific surface area of the catalyst and also increased the mass transfer of the catalyst.The catalyst has more microporous structure and mesoporous structure,it increases the specific surface area of the catalyst and increases the mass transfer.In order to further improve the activity and stability of the catalyst,the method of microwave ethylene glycol was used to prepare the composite catalyst Pt/Ru-N-C by using the optimized Ru-N-C as the carrier and loading Pt particles on it.The effect of different alkali dosage and different microwave time on the performance of Pt/Ru-N-C catalyst was investigated.The catalyst prepared with 2.00 m L of alkali and 100 s of microwave time had the best performance.The peak fitting of Pt 4f by XPS shows that Ru-N-C carrier has a regulatory effect on the electronic structure of Pt.