Aging aspects of DEB getters

The changes in uptake capacity of 1,4-bis(phenylethynyl)benzene (DEB) blended with carbon-supported Pd (DEB-Pd/C) in the form of pellets as a function of temperature and time were investigated. Experimental results revealed a segregation and crystallization of DEB molecules toward the geometrical surfaces of the getter pellets, but very little or no diffusion-aggregation of Pd nano-catalysts even after long term storage at 75 °C in nitrogen. Despite the observation of surface segregation and crystallization of DEB molecules with increasing temperature and time, statistically there was no reduction in uptake capacity for the getter pellets stored at higher temperature. However, significant reversible reductions in uptake capacity was found among getter pellets exposed to air for extended time. The possible causes for these observations and their respective roles in the aging of getters are discussed.