Catalytic effect of fullerene and formation of nanocomposites with complex hydrides: NaAlH4 and LiAlH4

Carbonaceous nanomaterials utilized as scaffolds, catalysts, and additives in conjunction with complex metal hydrides have shown remarkable hydrogen sorption properties. Our studies have confirmed fullerene-C60 is an excellent catalyst for temperature induced hydrogen desorption for both NaAlH4 and LiAlH4. Fullerene-containing complex metal hydride composites comprised of fullerene-C60 with NaAlH4 or LiAlH4 desorbed hydrogen at elevated temperature and go onto form alkali metal fullerides and aluminum metal as final products. The as-prepared composites exhibit rapid hydrogen desorption at onset temperatures of 130 °C and 150 °C, and released hydrogen content of 5.9 and 2.2 wt.% (LiAlH4 and NaAlH4, respectively) relative to the composite. The resultant alkali metal fulleride containing composites have been characterized and are capable of reversible hydrogen storage. A series of desorption/absorption experiments on the Na–C60 and Li–C60 based composites demonstrate a 1.5 wt.% and a 1.2 wt.% reversible capacity, respectively. The complex metal hydride-C60 systems were characterized by PCT, XRD, FT-IR, and TGA-RGA and demonstrate the formation of fulleride material similar to traditional hydrofullerenes which appear to be responsible for the observed reversible hydrogen storage.

Research highlights▶ Catalytic effect of fullerenes on the reversible hydrogen storage ▶ Hydrogen storage properties of alkali metal hydrides and fullerene mix forming nanocomposites ▶ Novel ways of intercalating Na and Li atoms into C60 ▶ Destabilization of hydrides ▶ Potential to enable the formation of other high capacity hydrogen storage materials