Platinum (Pt) material is the most common cathodic catalyst in low temperature fuel cells. However, the electrochemical efficiency and oxygen reduction reaction is still very low. Based on these expensive Pt-based catalysts, researchers had focused on developing alternative catalysts over the past several decades. In this research, we simulated catalytic reaction process and analyzed the properties to improve the speed of reaction of fuel cells. This research focused on developing a practical low temperature fuel cells, and pointed out the key of improving efficiency.The real reaction process and mechanism were very complicated and implied variable changes. Several steps which affect the efficiency of low temperature fuel cells, including oxygen adsorption, oxygen dissociation, protonation, charge transfer, and water desorption among others. The main rate-limited step in cathodic reactions is the oxygen reduction reaction (ORR). This research uses quantum mechanics simulation to analyze the cathodic catalyst of proton exchange membrane fuel cells (PEMFCs). We use density functional theory (DFT) to build up nano structures of graphenes, single walled and multi-walled carbon nanotubes. In addition, we used adsorption and doping method to add Pt and Nitrogen (N) into the cathodic catalysts. CASTEP platform with periodical boundary conditions were used to optimize the nano structures during the oxygen reduction reaction process. The catalytic process such as oxygen adsorption energy, reorganization energy, rate of electron and hole transfer and work function were analyzed.  In conclusion, we obtain a realistic oxygen reduction reaction process and an improved catalyst applied in most of the selected nano structures and cathodic catalysts.

Computational quantum chemistry analysis of the cathodic catalyst in low temperature fuel cells

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.