Atomic and electronic structures of M (=Ni, Fe, NiFe, or FeNi) adlayer-modified alpha-Al2O3(0001) catalyst interface

Kenneth Wong, Qinghua Zeng, Aibing Yu

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6 Citations (Scopus)

Abstract

In this study, density functional theory calculation is applied to examine the interfacial electronic and physical structures between the monometallic (Fe, Ni) or bimetallic (NiFe, FeNi) adlayer-modified alpha-Al2O3(0001) support and its connection with catalytic activity, for example, methane cracking. It is shown that bimetallic interfaces display the key factors for highly catalytic activity as a result of a balance of system stability, favorable d orbital directionality for molecular adsorption, spin quenching, and electron accumulation at the interface. The most stable interfaces promoting the strong metal-support interaction are the monometallic Fe or Ni and bimetallic NiFe interfaces formed with alpha-Al2O3-(0001). Such interfaces are composed of polar/ionic bonds in which bimetallic modification experiences the most significant interfacial M-M (M = Fe or Ni) and Al-O-M bond expansion. In addition to the spin quenching of the metal adlayer, it is identified that interface lattice expansion/distortion upon metal modification can induce two different molecular adsorption environments where the diffusion and strong adsorption of molecules at the interface and top metal adlayer can occur, respectively.
Original languageEnglish
Pages (from-to)13796 - 13803
Number of pages8
JournalJournal of Physical Chemistry C
Volume115
Issue number28
DOIs
Publication statusPublished - 2011
Externally publishedYes

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