Ni–B-doped NaAlH_4 hydrogen storage materials prepared by a facile two-step synthesis method

摘要

By directly introducing Ni–B into NaAlH4 system using a facile two-step synthesis method, the effects of Ni–B on NaAlH4 were systematically investigated. NaAlH4 can be completely formed after 30 h milling under 1 MPa hydrogen pressure. In addition, the dehydrogenation kinetics of as-prepared NaAlH4 after different milling times were investigated. As the dehydrogenation temperature rises,both the hydrogen desorption capacity and dehydrogenation rate quickly increase. The apparent activation energy E a for Ni–B-doped NaAlH4 is calculated to be 61.91 k J mol-1 for the first dehydrogenation step. More importantly, the dehydrogenation temperature of as-prepared NaAlH4 nanocrystalline can be reduced to about 100 °C.