FIELD-INDUCED OXYGEN LAYER FORMATION FROM H2O AND ITS TITRATION BY HYDROGEN ON A PT-EMITTER

FEM and FIM studies are presented showing the field-induced formation of an O-ads island on the apex of a platinum field emitter. This occur s during the well known bimolecular, field-induced water dissociation reaction 2H(2)O(ads) --> H3Ogas+ + gas OHads + e((Pt))(-) which is fol lowed by a disproportionation reaction of the OHads species to H2O and O-ads without any noticeable face specifity. The titration reaction o f the O-ads layer with H-2 displays face specific conversion rates. FI M reveals chemical waves propagating with sharp boundaries on the atom ic scale. Implications for the oscillating H2O/H-2 reaction system are discussed.