AVS 50th International Symposium
    Surface Science Friday Sessions
       Session SS1-FrM

Paper SS1-FrM5
Elucidating the Origin of Low-Temperature Reactivity of the Ni-Pt Bimetallic System

Friday, November 7, 2003, 9:40 am, Room 327

Session: Catalysis IV: Reactivity of Complex Systems
Presenter: N.A. Khan, University of Delaware
Authors: N.A. Khan, University of Delaware
J.G. Chen, University of Delaware
Correspondent: Click to Email
Bimetallic surfaces possess unique physical, chemical and electronic properties unlike those of either parent metal. These surfaces have generated considerable interest as novel catalytic materials with higher reactivities and selectivities. As catalysts, they are used in numerous applications, such as fuel cells, hydrotreating (bimetallic sulfides and carbides) and hydrogenation catalysts. In our research, we have studied the Ni/Pt(111) and Pt/Ni(111) model bimetallic systems. We have found that the 1 ML Ni/Pt(111) surface demonstrates a low-temperature hydrogenation reaction pathway not present on either pure metal surface. DFT and LEIS studies indicate that this reaction pathway may be a result of Ni diffusing into the Pt(111) subsurface layers. In order to further study the interaction between Pt and Ni and the chemical properties of these bimetallic surfaces, we have also investigated the low-temperature reaction pathway on Pt/Ni(111). TPD studies reveal that the hydrogenation chemistry on the 1 ML Pt/Ni(111) surface is almost identical to that of the 1 ML Ni/Pt(111), revealing that the chemistry is independent of the order of metal deposition, i.e. Ni/Pt(111) or Pt/Ni(111). We will also demonstrate the strong correlation between model Ni-Pt surfaces and supported Ni-Pt bimetallic catalysts.