Mitigation of CO Poisoning on Functionalized Pt/TiN(001) Surface: A Fundamental Study of the Next-Generation Fuel Cell Technologies

摘要

It has been previously reported that the system of embedding single Ptatom in the N-vacancy site on TiN/(100) surface (Pt/TiN) could be a promising catalyst for proton exchange membrane fuel cells (PEM FCs). The adsorption properties of molecules on Pt/TiN are an important step, when it is incorporated as the anode or cathode of PEM FCs. Utilizing the first principle calculations based on density-functional theory, this proposal systemically investigates the adsorption of several atomic and molecular species on Pt/TiN system, as well as the coadsorption of these molecular fragments. The favourable binding sites and energies of adsorption of several molecular species, namely carbon dioxide (CO), carbon monoxide (CO), oxygen (O2), hydrogen (H2), hydroxyl (OH), oxygen atom (O), and hydrogen atom (H) are explored. For each the formation energies, preferred binding site and their associated vibration frequencies will be studied. Preliminary results of molecular adsorption indicate that these interactions could well be dominant surface interactions under operational conditions. To further study the fundamental impact of surface functional groups on CO mitigation in this catalyst system, the co-adsorption of CO and OH (or H) on the Pt/TiN surface are also investigated. In this proposal, we will attempt to study and explain the fundamental mechanism behind the mitigation of CO poisoning on functionalized Pt/TiN surfaces under both acidic and basic operation conditions in PEM FCs.