title: Surface design of alloy protection against CO-poisoning from first principles.
abstract: Pt-based alloy catalysts are of significant importance in fuel cells due to enhanced electrode reactivity and selectivity. Designing alloy surfaces suitable for catalyst via first-principles predictions has long played a central role in identifying promising candidates. We propose surface design for polymer electrolyte fuel cell (PEFC) based on the use of thermodynamically stable alloy surfaces. Using first-principles calculation, we have explored stable Pt alloy surfaces that possess superior catalytic properties for CO-despoisoning in hydrogen-related reactions of fuel cells. The stable Pt(25)M(75) (M = Rh, Cu) alloy surfaces both exhibited weaker CO and stronger H binding compared to the pure Pt surface, which yielded a significant increase in H coverage by around one order. These modifications of molecular adsorption are attributed to the deeper band centre of surface d electrons. Understanding the adsorption properties of the stable atomic structure at surfaces will help us to design suitable alloy surfaces with high-catalytic activity and prolonged actuation in fuel cells.
authors: Department of Materials Science and Engineering, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
authors: Koretaka
authors: K
authors: Yuge
authors: Yukinori
authors: Y
authors: Koyama
authors: Akihide
authors: A
authors: Kuwabara
authors: Isao
authors: I
authors: Tanaka
mesh_terms: D000327:Adsorption; D000497:Alloys / Q000737:chemistry*; D002248:Carbon Monoxide / Q000737:chemistry*; D002249:Carbon Monoxide Poisoning / Q000517:prevention & control*; D002384:Catalysis; D004573:Electrolytes; D004583:Electrons; D006859:Hydrogen / Q000737:chemistry*; D008956:Models, Chemical; D010100:Oxygen / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000497:Alloys; D004573:Electrolytes; D011108:Polymers; D010984:Platinum; D002248:Carbon Monoxide; D006859:Hydrogen; D010100:Oxygen