Enhanced catalyticdehydrogenation of LiBH4 by carbon-supported Pdnanoparticles

Abstract

The investigation of thermally induced dehydrogenation of LiBH₄ catalyzed by carbon-supported Pd nanoparticles (Pd/C) reveals that LiBH₄ doped with the Pd/C catalysts shows superior dehydrogenation performance, compared to dehydrogenation in the absence of catalyst, even at very low catalyst content. We have found that smaller Pd nanoparticles result in greater enhanced catalytic dehydrogenation of LiBH₄ than do larger Pd nanoparticles. For doping with 10 wt.% catalyst of an average Pd particle diameter of ca. 5.3 nm, thermal dehydrogenation of LiBH₄ is found to start at ca. 280 °C with a total weight loss of 15.8 wt.% for the full temperature range. With increased loading of catalyst within a LiBH₄ sample, the onset dehydrogenation temperature and the two main desorption peaks from LiBH₄ are found to decrease while the hydrogen release amount is found to increase. All the hydrogen of ca. 18.5 wt.% can be released from LiBH₄ below 580 °C at a catalyst doped level of 50 wt.%. Importantly, we observed a reversible hydrogenation/dehydrogenation with a capacity of approximately 4.3 wt.%. Pd nanoparticles are found to play an important role in the catalyzed dehydrogenation/rehydrogenation of LiBH₄.