Hydrogen storage cycling of MgH2 thin film nanocomposites catalyzed by bimetallic Cr Ti

We examine hydrogen sorption cycling of 1.5 μm thick magnesium thin films containing a bimetallic chromium titanium catalyst. At 200 °C these nanocomposites absorb 5 wt % hydrogen in several seconds, and desorb in 10–20 minutes. In several compositions, there is negligible hydrogenation kinetics or capacity degradation even at over 100 cycles. Equally importantly, the ternary films require minimal activation, achieving rapid magnesium hydride formation and decomposition from cycle one. Pressure-composition isotherms display well-known enthalpies of MgH2. Transmission electron microscopy analysis supports a hypothesis that such extreme kinetics is due to the presence of a nanodispersed Cr Ti phase in Mg matrix.