DECOMPOSITION OF FORMALDEHYDE ON CU-NI(110) SINGLE-CRYSTAL SURFACES

The decomposition of formaldehyde on a clean (110)-oriented Cu Ni single crystal was studied by flash desorption spectroscopy and Auger electron spectroscopy. The copper/nickel alloy surfaces were varied in composition from 100% Ni to 35% Ni. At 190 °K formaldehyde appeared to adsorb dissociatively to form H(a) and CO(a). The desorption of CO was first order while the desorption of H2 obeyed complex kinetics. The H2 and CO production from H2CO decreased with increasing surface copper content. This effect was due to the requirement of a cluster of two nickel atoms on the surface to decompose the formaldehyde molecule. The possible stabilization of an H-CO surface intermediate on the Cu-rich surfaces is discussed. © 1979.