Characteristic Evaluation of High Corrosion Resistant Ti/ (Pt + B2O3) Electrode with New Microstructure of Coat
In order to improve the durability of Pt coated Ti electrodes as an anode of the sulfuric acid system electrolysis, tantalum oxide (Ta2O5) additions have been used widely. However that is not enough for uses under severe conditions. In this study,boric acid (H3BO3) was added into the Pt coating during manufacturing process of Ti/Pt-coated electrodes, and the (Pt + B2O3)/Ti electrodes were obtained. The effect of H3BO3 addition on the microstructure, surface area, and lifetime of (Pt + B2O3)/Ti electrodes was also investigated in detail. Commercially available titanium plates (10 100.5mm) were employed for prepare Ti/ (Pt + B2O3) electrodes, where it was confirmed by XRD that B2O3 formed by heating the boric acid was amorphous in the temperature range of 250 to 550. The coating solution of 2 μl of H2PtCl66H2O (Pt:50 g/l) dissolved in butanol and 5~20 mass% H3BO3 mixture was spread over the etched Ti plates. After drying at 70 for 30 min, the substances were heated at 250 to 550 for 10 min. The lifetime of the electrodes was examined by a direct current of 1 A using Pt plate as the counter electrode in 1 M H2SO4 solution at 40. The end of life was determined as the time when the cell voltage changed 2 times of the beginning.
T. Ohji, T. Sekino and K. Niihara
D. Y. Ju et al., "Characteristic Evaluation of High Corrosion Resistant Ti/ (Pt + B2O3) Electrode with New Microstructure of Coat", Key Engineering Materials, Vols. 317-318, pp. 393-398, 2006