MOF-based Porous Carbon Nanocomposites And Their Electrocatalytic Properties

Due to its high conversion rate,clean and pollution-free advantages,fuel cells have received extensive attention.However,the slow reaction of oxygen reduction of proton exchange membrane fuel cells greatly limits their large-scale commercial application.Therefore,it is necessary to use cathode electrocatalysts to increase oxygen reduction.Reaction rate,at present,Pt-based catalysts have become highly efficient oxygen reduction cathode catalysts with good electrocatalytic activity.Because of their high price,scarcity,poor stability,and susceptibility to corrosion,they have hindered their wide application in energy systems.Therefore,the exploration of non-precious metal electrocatalysts with low price,high electrocatalytic activity,good stability,and rich global storage will Its large-scale application in green energy equipment.This paper is a catalyst for the preparation of doped carbon materials using MOF as a precursor.The main contents are as follows:?1?Co-MOFwaspreparedbyhydrothermalmethod.Thecorresponding Co/NPC?Co/nitrogen-doped porous carbon?composites were prepared by direct pyrolysis without adding any precursors.Conducting an oxygen reduction electrocatalytic reaction,the final surface of the Co/NPC catalyst has a good ORR electrocatalytic activity at 600°C,with an initial potential of 0.90 V and a current density of-5.49 mA/cm².The oxygen reduction of the polarization curves by RDE and RRDE gave an average electron transfer number of 3.92 indicating that the Co/NPC catalyst can pass the perfect 4e-pathway.After ORR test at 0.50 V?vs RHE?for 9.5 h,the current of Co/NPC only decreased by about 5%,while the current of commercial Pt/C catalyst decreased by about 28%,resulting in a better Co/NPC catalyst.Stability.?2?Hydrothermally prepared MOF materials were carbonized at different temperatures,and their oxygen reduction electrocatalytic reactions were studied to obtain the best oxygen reduction electrocatalytic materials,which were added to ex-C₃N₄,namely CoNC-700,and its optimization results finally that the ORR starting potential and half-wave potential of CoNC-700 catalyst are 0.92 V and The 0.71 V is comparable to the commercial 20%Pt/C catalysts?0.92 and 0.73 V?and their ultimate diffusion current density at 0.40 V is much more negative than the CoNC-700catalyst is 20%Pt/C(CoNC-700 And 20%Pt/C were-6.07 and-5.35 m A cm^-2),the catalyst has good electrocatalytic activity,and the material has good stability.?3?Synthesis of ZIF-67,doped with sodium phytate,the resulting compounds were N/P/CO-C-600,N/P/CO-C-700,and N/P/CO-C-800 when carbonized at different temperatures.ZIF-P-1:2-700 has good electrocatalytic activity for oxygen reduction,ie,the starting potential is 0.96 V,and the current density is-6.10 m A/cm².This material has4 electronic history and good stability.