PLATINIZED-TITANIUM ELECTRODES FOR UREA OXIDATION .2. CONCENTRIC SPIRAL COIL GEOMETRY

Highly active urea electro-oxidation catalysts were prepared by electrodeposition of Pt onto Ti in a novel, concentric spiral coil geometry. The concentric spiral coil geometry can be used directly in construction of electrochemical reactors. The Pt deposition from chloroplatinic acid required about 1.5 times the stoichiometric charge. Projection of urea conversion activity from cyclic voltammetry measurements to a clinical-scale, portable hemodialysis system indicates that approximately 10 g of Pt will be required for the clinical-scale system. The specific urea conversion activity, as measured by cyclic voltammetry, is linearly related to the specific Pt surface area of the deposition. The depositional growth morphology is found to be self-similar, with a fractal dimension that lies somewhere between uniform deposition and hemispherical growth.