IN-SITU ELECTRODE FORMATION IN A SWISS ROLL REACTOR

The Swiss roll electrochemical reactor design, which is comprised of c oncentric spiral electrode coils, has a superior electrode packing den sity and reaction capacity in comparison with more conventional design s. Because platinized-titanium surfaces are mechanically unstable at l ow platinum loadings, use of the Swiss roll design with such electrode s requires in situ electrodeposition of platinum onto the titanium sur faces after fabrication. Methodology is described to examine the resul tant Pt distribution across the width and along the length of expanded Ti mesh after in situ electrodeposition. Four major control variables , i.e., total electroplating charge, plating current density, number o f pulses used to deliver the charge, and first coil to receive a curre nt pulse, explain 86% of the experimental variance in a linear effects model. Resulting Pt distribution, when normalized for the extent of p latinization, is surprisingly uniform on the entire extent of the elec trode coils. The major discrepancies from uniform deposition occurred on the Ti electrode coil which acted as the counter electrode during t he first electrodeposition, indicating a surface modification which af fects the electrodeposition process.