A 100 W PAFC stack with 12 cells was assembled using in-house developed PTFE-bonded gas diffusion porous carbon electrodes, graphite bipolar plates and aluminium external gas manifolds. The stack was operated for 1000 h continuously with acid management, using H-2 and air at 1 bar and at 175 degrees C. After completion of the test the stack was disassembled and the electrodes were characterized using X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) techniques. The XPS and ICP-AES results revealed the presence of platinum in the electrolyte matrix layers (SIC + PTFE) and carbon mat layers (carbon + PTFE), which were applied on the cathodes and the anodes, respectively. This clearly indicates that there was a migration of platinum from cathodes to anodes during the stack operation. This may have occurred when operating the stack at it＇s open circuit voltage (OCV) while taking measurements of stack voltage and current for the I/V curves.