|About this Abstract
||Materials Science & Technology 2012
||Nanotechnology for Energy, Environment, Healthcare and Industry
||Nanosegregated Catalysts for Polymer Electrolyte Membrane Fuel Cells: Theoretical Modeling
||Guofeng Wang, Zhiyao Duan
|On-Site Speaker (Planned)
Platinum (Pt) alloy nanoparticles are the most efficient catalysts to promote the electrochemical reactions in polymer electrolyte membrane fuel cells. The performance of these Pt alloy electrocatatalysts are determined by the arrangement of different elements in their surface regions. In this work, we employed an atomistic Monte Carlo simulation method to model the surface segregation processes and predict the equilibrium structure and surface composition of various nanosegregated Pt alloy nanoparticles. Specifically, we have examined our computational approach for several Pt bimetallic alloys that represent different fashions of Pt segregation to the surfaces: Pt-Ni (strong and oscillatory surface segregation), Pt-Re (strong and monotonic surface segregation), Pt-Mo (weak and monotonic surface segregation), Pt-Ti (surface segregation sensitive to bulk composition), and Pt-Fe (surface segregation in ordered alloys). Furthermore, we used density functional theory calculation method to investigate how the surface segregation affects the kinetics of chemical reactions on the nanosegregated Pt alloy catalysts.