Disc-shaped anodes

SAXS measurements were made at the National Center for Small Angle Scattering Research (NCSASR) at Oak Ridge National Laboratory using the 10m SAXS camera. The instrument used a rotating anode CuK (X" 0.1542 nm) x-ray source, crystal monochromatization of the incident beam, pinhole collimation, and a two dimensional, position sensitive, proportional counter. Sample to detector distance was 1.12 m. Disc-shaped samples were cut from the molded films and dried in a vacuum oven at 65 °C for four weeks prior to the SAXS analyses. 

The O2 reduction on Ag [28,64,65], Ni [66], and Ni-Ag alloys [66] was studied with the ring-disc assembly in recent years. The i — U curves in Fig. 80 were measured [66] at 1000 rotations/min on the disc in 0.1 M KOH. The disc was made of silver for curves a and a and of nickel for curves b and b. The disc surface was polished mechanically with quartz powder and subsequently polarized cathodically for curves a and b (prereduced electrodes). Anodic polarization with lOmA/cm for 2 min served as the pretreatment for curves a and b (preoxidized electrodes). The curves a, a, and b are similar in shape to the i — U curves on platinum metals in Fig. 72. The net process is limited by the O2 diffusion at I/<0.4V. The decrease of / with increasing potential occurs on prereduced nickel in the potential range where the surface... 

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