OSCILLATING HYDROGEN-WATER REACTIONS ON A PLATINUM FIELD EMITTER

The spatial and temporal behavior of surface reaction-diffusion-fronts has been examined during oscillating H2/H2O reactions on a Pt field ion emitter. Mass and energy resolved measurements, discriminating between different reaction pathways, have been made of local yields of ions such as H3O+ and H3O+.H2O. Periodic out-bursts of ion yields correlate with the passage of wave fronts across the emitter apex imaged by field ion microscopy. The experimental observations together with the predictions of a kinetic lattice gas model suggest that the supply of hydrogen, primarily by surface diffusion from the emitter shank plays a vital role.