Study on the Transition Metal Compound Catalysts for Cathode of PEMFC
|School||Wuhan University of Technology|
|Course||New Energy Material|
|Keywords||Proton exchange membrane fuel cell Non - precious metal catalyst Oxygen reduction reaction Catalytic activity|
The proton exchange membrane fuel cell (Proton exchange membrane fuel cells, PEMFCs) because of the low emissions and high efficiency is considered to be most suitable for mobile and fixed- power requirements of the power generation device . Pt / C catalyst in the development process of the fuel cell , the high cost is one of the bottlenecks that hinder its commercialization . Reduce the Pt loading and the study of non - precious metal catalyst has become the hotspot of proton exchange membrane fuel cell research . This article the the Nano level of Co3O4 and Co3O4 / C catalyst was prepared by liquid control precipitation method ; homogeneous precipitation prepared nanoscale iron oxide precursor , and then temperature programmed ammonia the solution prepared Fe2N catalyst . By means of XRD , TEM structural characterization of the catalyst , and linear sweep voltammetry (LSV) and cyclic voltammetry (CV) method of the oxygen reduction catalytic properties of the catalyst was tested . Materials studio on the the Co3O4 surface of oxygen adsorption process simulation to explore the catalytic mechanism . The results show that : ( 1 ) Preparation of Co3O4 and Co3O4 / C , the average particle size were 15nnm and 10 nm . (2) Co3O4 and Co3O4 / C has a catalytic activity for the oxygen reduction reaction , the electron transfer number of 3.3 oxygen reduction process is a two-electron and four - electron reduction of the mixing process . (3 ) end - adsorption mode, primarily to weaken through the interaction between the cobalt and adsorption of the terminal oxygen atom of oxygen molecules in a π bond, and activation of the terminal oxygen atom unadsorbed , hydrogen ions are easy the other side with unadsorbed terminal oxygen atoms to form a new chemical bond , the two electron reaction occurs . Dual Address adsorption occurs , the two oxygen atoms simultaneous adsorption and activation of enhanced electron delocalization sex . Dual Address adsorption the adsorption of the activation of the two oxygen atoms is greater than the end groups , and easy occurrence of four -electron reaction . (4) iron nitride prepared for the oxygen reduction in catalytic activity is very low , it may be due to the adsorption energy is too high and difficult to desorption caused . Further, there is no carbon carrier is also one of the reasons of lower catalytic performance .