The interaction of pure CO2 with a 3 mu m thin, supported Pd membrane has been investigated between 473 and 773 K. Diagnostic H-2 permeation measurements indicate a reduction of the H-2 flux after CO2 exposure at the lower and upper ends of this temperature range. Temperature-programmed oxidation and desorption in combination with scanning electron microscopy analyses reveal the dissociation of CO2 above 523 K, yielding molecularly and/or dissociatively adsorbed CO below 623 K and nanoscopic carbon deposits above 723 K. CO2 is obviously not inert over Pd surfaces at practical Pd membrane operation temperatures but could be kinetically stabilized in a narrow temperature window around 673 K.