AVS 50th International Symposium
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP33
Dissociation of Methyl Iodide on the Al(111) Surface - An STM and DFT Study

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: S. Mezhenny, University of Pittsburgh
Authors: S. Mezhenny, University of Pittsburgh
D.C. Sorescu, U.S. Department of Energy
P. Maksymovych, University of Pittsburgh
J.T. Yates, Jr., University of Pittsburgh
Correspondent: Click to Email
The reaction of methyl iodide (CH@sub 3@I) with the Al(111) surface was studied by room temperature scanning tunneling microscopy (STM) and by first principles calculations. It was found that at 300K CH@sub 3@I decomposes on the Al(111) surface forming methyl, CH@sub 3@, methylidyne, CH, and adsorbed iodine. CH@sub 3@ groups were observed to occupy atop sites by STM, while CH species occupy hollow sites. Total energy density functional theory calculations have shown that CH@sub 3@ species occupy atop Al sites (E=45.3 kcal/mol), CH species adsorb on fcc hollow sites (E=155.0 kcal/mol), while individual iodine atoms can bind on both top or hollow sites with adsorption energies 54-56 kcal/mol.