ADSORPTION AND DECOMPOSITION OF METHANOL ON NIAL(110)

Methanol adsorption and reaction on NiAl(110) have been investigated w ith temperature-programmed desorption, X-ray and ultraviolet photoelec tron spectroscopy, and high-resolution electron energy loss spectrosco py. Methanol chemisorbs associatively (at least at relatively high cov erage) on NiAl(110) at 120 K and transforms into surface methoxy by 20 0 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 a lso 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 th at 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,