Journal of Physical Chemistry, Vol.98, No.40, 10258-10268, 1994
Adsorption and Decomposition of Methanol on NiAl(110)
Methanol adsorption and reaction on NiAl(110) have been investigated with temperature-programmed desorption, X-ray and ultraviolet photoelectron spectroscopy, and high-resolution electron energy loss spectroscopy. Methanol chemisorbs associatively (at least at relatively high coverage) on NiAl(110) at 120 K and transforms into surface methoxy by 200 K. Decomposition of the methoxy overlayer leads to the evolution of gaseous H-2, CO, CH4, and CH3 radicals, in addition to the deposition of surface oxygen and carbonaceous species. The formation of C2H4 is also observed after a high coverage of methoxy decomposes on NiAl(110). Methyl radical desorption occurs near 570 K and CH4 desorbs near 350 K from NiAl(110). The low-temperature CH4 desorption peak indicates that the C-O bond of a fraction of surface methoxy is cleaved below 350 K on NiAl(110), in contrast to monometallic Al and Ni, emphasizing the unique reactivity of this alloy surface,
Keywords:ENERGY-LOSS SPECTROSCOPY;TRANSITION-METAL ALUMINIDES;STIMULATED DESORPTION;THERMAL-DECOMPOSITION;ELECTRONIC-STRUCTURE;NI/AL2O3 CATALYSTS;NEUTRAL MOLECULES;ORGANIC-MOLECULES;SURFACE KINETICS;UV PHOTOEMISSION