Preparation And Electrochemical Behavior Of Graphitized Carbon Black/Platiunm Nanohybrid Catalyst

Pt/C nanohybrid catalyst is the most widely used catalyst for gas diffusion electrode, but its catalytic activity and stability are the key problems for its further development. Moreover, the catalytic activity and stability of Pt/C deeply depend on the characteristics of carbon supports. In my research, I successfully prepared a kind of graphitized carbon black with a high graphitization degree by a heating treatment to Vulcan XC-72. The GCB was proved to have a good graphitization degree by HRTEM, Raman scattering spectra and XRD, a lower specific surface area and fewer micropores than Vulcan XC-72 by BET and pore distribution test. We also prepared highly dispersed Platinum supported on graphitized carbon black (Pt/GCB) electrocatalyst by ethylene glycol reduction method. The Pt/GCB electrocatalyst were characterized both physically (XRD, HRTEM and TGA) and electrochemically (CV and EIS). The electrocatalyst thus prepared show a high dispersion of Pt nanoparticles, with diameters in the 2-5nm range and a very narrow particle size distribution. These catalytic systems possess higher electrochemical active surface area and catalytic activity towards oxygen reduction reaction. Moreover, they have a high resistance against oxidation, which is considerably greater than that of the Platinum supported on Vulcan XC-72 (Pt/XC) system.We adopted GCB, Vulcan XC-72 and BP2000, which have different structural and surface characteristics, to prepare the microporous layers of gas diffusion electrodes respectively and the Pt/GCB was used as catalyst to prepared catalyst layers. We found that the gas diffusion electrode whose microporous layer was made of GCB had a highest efficiency for oxygen reduction reaction and thus a best electrode performance by CV, Galvanostatic and EIS tests, due to its better performance on conductivity, hydrophobicity and pore distribution.