a b s t r a c tThe physical and chemical properties of 1,4-diphenylbutadiyne (DPB) blended with carbon-supported Pd (DPB-Pd/C) in the form of pellets during hydrogenation were investigated. A thermogravimetric analyzer (TGA) was employed to measure the kinetics of the hydrogen uptake by the DPB getter pellets. The kinetics obtained were then used to develop a semi-empirical model, based on gas diffusion into solids, to predict the performance of the getter pellets under various conditions. The accuracy of the prediction model was established by comparing the prediction models with independent experimental data on hydrogen pressure buildup in sealed systems containing DPB getter pellets and subjected to known rates of hydrogen input. The volatility of the hydrogenated DPB products and its effects on the hydrogen uptake kinetics were also analyzed.Published by Elsevier B.V.

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Due to the exothermic reaction of lithium hydride (LiH) salt with water during transportation and handling, there is always a thin film of lithium hydroxide (LiOH) present on the LiH surface. In dry or vacuum storage, this thin LiOH film slowly decomposes. We have used temperatureprogrammed reaction/decomposition (TPR) in combination with the isoconversion method of thermal analysis to determine the outgassing kinetics of H 2 O from pure LiOH and H 2 and H 2 O from this thin LiOH film. H 2 production via the reaction of LiH with LiOH, forming a lithium oxide (Li 2 O) interlayer, is thermodynamically favored, with the rate of further reaction limited by diffusion through the Li 2 O and the stability of the decomposing LiOH. Lithium hydroxide at the LiOH/vacuum interface also decomposes easily to Li 2 O, releasing H 2 O which subsequently reacts with LiH in a closed system to form H 2 . At the onset of dry decomposition, where H 2 is the predominant product, the activation energy for outgassing from a thin LiOH film is lower than that for bulk LiOH. However, as the reactions at the LiH/Li 2 O/LiOH and at the LiOH/vacuum interfaces proceed, the overall activation energy barrier for the outgassing approaches that of bulk LiOH decomposition. The kinetics developed here predicts a hydrogen evolution profile in good agreement with hydrogen release observed during long term isothermal storage.2

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