AVS 59th Annual International Symposium and Exhibition
    Surface Science Wednesday Sessions
       Session SS-WeA

Paper SS-WeA11
Composition Spread Alloy Films for Study of Alloy Catalysis Across Composition Space

Wednesday, October 31, 2012, 5:20 pm, Room 21

Session: Catalysis on Metals and Alloys
Presenter: A.J. Gellman, Carnegie Mellon University
Authors: A.J. Gellman, Carnegie Mellon University
B. Fleutot, Carnegie Mellon University
P. Kondratyuk, Carnegie Mellon University
J.B. Miller, Carnegie Mellon University
G. Gumuslu, Carnegie Mellon University
Correspondent: Click to Email
Composition spread alloy films (CSAFs) are alloy libraries that contain a continuous distribution of alloy compositions (AxByC1-x-y). Spatially resolved measurements of catalytic reactivity across CSAF libraries map catalytic reactivity as function of alloy composition. In many implementations CSAFs span continuous regions of ternary alloy composition space, but not the entire composition space. We describe the design and implementation of a method for deposition of a 1x1 cm2 CSAF that contains all possible compositions of a ternary alloy (AxByC1-x-y with x = 0 → 1 and y = 0 → 1-x), all three binary alloys (AxB1-x, AxC1-x, and BxC1-x with x = 0 → 1) and all three pure component species. These CSAFs can be characterized using a number of methods including energy dispersive spectroscopy, electron back scatter diffraction, x-ray photoemission spectroscopy, and low energy ion scattering spectroscopy. The bulk structure of CuxPd1-x binary CSAFs matches that of the bulk phase diagram. XPS and LEISS show that teh surfaec is enriched in Cu across the entire composition space. The catalytic reactivity of CuxPd1-x binary CSAFs a CuxAuyPd1-x-y ternary CSAF have been mapped across composition space using a 100 channel microreactor array. The reactivity changes with bulk composition can be correlated to the electronic structure of the alloys. The suite of methods allows a comprehensive study and understnading of alloy catalysis across composition space.