| Title |
Hydrogen Entry into Pulse - Plated Palladium Deposits |
| Authors |
김창하(Chang Ha Kim); 변수일(Su Il Pyun); 송락현(Rak Hyun Song) |
| Abstract |
The hydrogen entry into pulse-plated palladium deposits on copper and iron has been investigated as a function of pulse current parameters such as duty cycle and average current density. The maximum cathodic current efficiency of palladium plating on copper was found to appear at the duty cycle of 60% and the average current density of 2 ㎃ ㎝^(-2). Hydrogen extraction and permeation tests indicate that the amount of hydrogen absorbed into the palladium deposits on copper and iron decreased with decreasing duty cycle due probably to a decrease in the input hydrogen concentration at the deposit surface during the palladium plating. The palladium deposit on iron provides a catalytic effect rather than a barrier effect on the hydrogen entry into the deposit. From impedance measurements it is concluded that the resistance to hydrogen reduction is larger than that to hydrogen oxidation at the surface of the palladium deposit on copper. This is based upon hydrogen adsorption on the surface of the palladium deposits. |