Preparation And Performance Characterization Of Cathode And Anode Electrocatalysts For Direct Methanol Fuel Cells

The large-scale application of clean and renewable technologies such as fuel cells and hydrogen production relies to a large extent on the efficiency of electrocatalytic reactions.Platinum(Pt)-based nanoparticulate metals have received great attention and are the most popular catalysts for direct methanol fuel cells(DMFCs).However,in the reaction of a methanol fuel cell,similar to the single metal Pt catalyst,the high cost of the Pt-based catalyst,the slow kinetics of the reaction process,and the formation of intermediate "toxic" molecules such as CO are major challenges.Past research has focused on the use of Pt alloys such as Fe,Ni,Co,Rh,Ru,Co and Sn metals,or carbon support materials to enhance the catalytic performance of Pt.In recent years,Pt and Pt alloy catalysts supported by the enormous potential of carbon materials such as CNTs,MWCNTs,CNFs and graphene have significant advantages because of their remarkable characteristics and can contribute to excellent MOR.At the same time,the development of non-precious metals with high catalytic efficiency,the earth's rich and inexpensive catalysts for electrocatalytic reactions,plays a vital role in sustainable energy conversion and storage.Due to their fascinating functions and diversity,some achievements have been made in the synthesis and application of metal organic framework(MOFs)electrocatalysts.For the direct methanol fuel cell,the anode Pt-based nitrogen-doped self-assembled carbon nanotube support catalyst and the cathode non-Pt carbon-based defect MOFs catalyst were designed and prepared.The use of a good conductivity and relatively strong,stable carbon material as a carrier for the anode and cathode catalysts enhances the catalytic performance for methanol oxidation and oxygen reduction.The main work is:Urea is used as a carbon source and a nitrogen source to add a metal salt,and then a nitrogen-doped self-assembled carbon nanotube carrier containing an alloy is synthesized in one step,and Pt is supported as a highly active Pt/CoNiCu-CNTs catalyst.The nitrogen-doped carbon nanotubes act as a carrier to interact with the catalyst,and by changing the electronic structure of the platinum atoms,the dispersion of the supported platinum nanoparticles is effectively improved and the MOR is promoted.Compared with commercial Pt/C,the electrochemical area and catalytic activity of Pt/CoNi2Cu-CNTs catalysts increased by 1.57 and 2.77 times,respectively,and the anti-toxicity of the catalyst was also significantly enhanced.MOFs were used as the master template to develop a defect MOFs catalyst Co3-MOFs-KJ by assembling Co-ZIF-67 on carbon black to obtain a precursor and then calcining pyrolysis in N2 gas.The catalyst exhibits high catalytic activity,and the initial potential and half-wave potential(E1/2)are close to the commercial Pt/C catalyst,and the long-term stability reaches 63%of Pt/C,which is better methanol durability than that of the Pt/C catalyst.This work broadens the application of MOFs in the field of electrocatalyst reduction reactions.