Enhanced catalytic hydrogen release of LiBH4 by carbon-supported Pt nanoparticles

Abstract

Thermally induced dehydrogenation of LiBH4 catalyzed by carbon-supported Pt nanoparticles (Pt/C) shows superior dehydrogenation performance compared to dehydrogenation in the absence of catalyst, even at very low catalyst content. Pt nanoparticles are found to play a crucial role in the catalyzed rehydrogenation/dehydrogenation of LiBH4. For doping with 10 wt.% catalyst of an average Pt particle diameter of ca. 4.7 nm, thermal dehydrogenation of LiBH4 is found to start at ca. 280 °C with total weight loss of 16.3 wt.% for the full temperature range. With increased loading of catalyst within a LiBH4 sample, the dehydrogenation temperature at which the major loss of hydrogen occurs is found to decrease while the hydrogen release amount is found to increase. All the hydrogen, ca. 18.4 wt.%, can be released from LiBH4 below 560 °C at a catalyst doped level of 50 wt.%. Importantly, we observed a reversible hydrogenation/dehydrogenation with a capacity of approximately 6.1 wt.%, which is very close to the theoretical capacity of the mixture of Li5PtH3 and B16H20 that is likely formed during the hydrogenation/dehydrogenation process.