A trend in the C-O bond strength of CH3Oad on NiAl(100), FeAl(100) and TiAl(010). Effect of the alloy Fermi level

Research is presented that investigates the C-O bond stability of surface methoxy bound on Al-terminated NiAl(100), FeAl(100), and TiAl(010). Temperature-programmed desorption suggests that a fraction of methoxy individually bound on the Al component of all three surfaces undergoes C-O bond cleavage to evolve gaseous methyl radicals. The trend in the temperature of maximum methyl ejection rate, T-m, is as follows: T-m(NiAl)> T-m(FeAl)> T-m(TiAl), suggesting that the nature of the transition metal in the underlying layer affects of the C-O bond energy. Results are shown that suggest that the position of the Fermi level in these materials plays a role in determining the C-O bond strength, consistent with the prediction of recent theory by Shiller and Anderson.