Microstructure optimization of Pt/C catalysts for PEMFC

Development of optimal methods for the synthesis and for the control of multi-level microstructure of Pt/C materials is essential for the preparation of electrocatalystsElectrocatalysts , which have high activity and durability. Nucleation/growth of metallic nanoparticlesNanoparticles could take place in the liquid phase, on the surface and in the pores of the carbon microparticles during the process of chemical reduction of Pt precursor in a liquid phase. These processes are sensitive to the composition of the medium, temperature, pH, mass transfer conditions, and other factors. On the one hand, that creates more opportunities to search the optimal conditions of synthesis. On the other hand, it makes difficult to control the reproducibility of the composition/structure of Pt/CPt/C . Pt/CPt/C materials with metal fraction from 10 to 20 wt% were obtained in this work. An average size of Pt crystallites was from 1.0 to 5.5 nm, depending on the method and conditions of synthesis. Electrochemically active surface area of catalysts measured by hydrogen electrodesorption method, was from 32 to 152 m2/gPt.