The synthesis of formaldehyde from methanol on oxygen-predosed Cu(110) surfaces has been studied using scanning tunneling microscopy (STM). Sequential STM images show the shrinking of the (2×1) Cu-O islands in the [001] direction and the formation of a (5×2) methoxy-induced reconstruction that incorporates the added-row Cu atoms of the (2×1) reconstruction. The decomposition of methoxy to formaldehyde occurs upon desorption; STM images show methoxy islands shrinking in the [001] direction and the release of incorporated Cu atoms.

• Received 22 June 1993

DOI:https://doi.org/10.1103/PhysRevLett.72.2569