PRODUCTION OF HYDROGEN GAS FROM NOVEL CHEMICAL HYDRIDES

Six ligand-stabilized complexes have been synthesized and tested for u se as hydrogen storage media for portable fuel cell applications. The new hydrides are: [HC(3,5-Me(2)pz)(3)]LiBH4 (1), {[H2C(3,5-Me(2)pz)(2) ]Li(BH4)}(2) (2) (pz = pyrazoryl), [(TMEDA)Li(BH4)](2) (3) (TMEDA = (C H3)(2)NCH2CH2N(CH3)(2)), [HC(pz)(3)]LiBH4 (4), {[H2C(pz)(2)]Li(BH4)}(2 ) (5) and Mg(BH4)(2)3THF (6) (THF = tetrahydrofuran). Hydrolysis react ions of the compounds liberate hydrogen in quantities:which range from 56 tb 104 (+/-5%) percent of the theoretical yield. Gas chromatograph ic analysis of the product gases from these reactions indicate that hy drogen ii rile only gas produced. Thermally initiated reactions of the novel compounds with NH4Cl were unsuccessful. Although hydrogen energ y which can be theoretically obtained per unit weight is lower than th at of the classical hydrides such as LiBH4 and NaBH4, the reactions ar e less violent and hydrolysis of compounds 1, 2, 4, 5 and 6 releases l ess heat per mole of hydrogen generated. (C) 1998 International Associ ation for Hydrogen Energy.