Comment on 'Gross rearrangement of metal atoms during surface reactions' by Bowker et al

In a recent paper Bowker et al (J. Phys.: Condens. Matter 10 7713) attempt to explain the enhanced reactivity occurring at the ends of Cu(110)-(2 x 1) O structures by proposing that the Cu-O rows are unstable unless terminated by oxygen atoms. We present alternative views based upon scanning tunnelin g microscopy (STM) observations. We show that consecutive images of the (2 x 1)O structures show the ends of the rows constantly dissolving and reform ing. Bowker at al also discuss the fates of Cu atoms released from the (2 x 1)O structures during reactions that produce adsorbed methoxy and formate, We discuss these interpretations with regard to reaction stoichiometries a nd models for methoxy structures as well as previous work on the formate sy stem.