In this study, we demonstrate that tetra-n-butylammonium borohydride [(n-C4H9)(4)NBH4] can be Used to form a hybrid hydrogen storage material. Powder X-ray diffraction measurements verily the formation of tetra-n-butylammonium borohydride semiclathrate, while Raman spectroscopic and direct,as release Measurements confirm the storage of molecular hydrogen within the vacant cavities. Subsequent to clathrate decomposition and the release of physically bound H-2, additional hydrogen was produced from the hybrid system via a hydrolysis reaction between the water host molecules and the incorporated BH4- anions. The additional hydrogen produced from the hydrolysis reaction resulted in a 170% increase in the gravimetric hydrogen storage capacity, or 27% greater storage than fully Occupied THF + H-2 hydrate. The decomposition temperature of tetra-n-butylammonium borohydride semiclathrate was measured at 5.7 degrees C, which is higher than that for pure THF hydrate (4.4 degrees C). The present results reveal that the BH4- anion is capable of stabilizing tetraalkylammonium hydrates.