Effect of Ce on the structure and hydrogen storage properties of V55Ti22.5Cr16.1Fe6.4

In this paper, the effect of rare metal element Ce on the microstructure, activation performance and hydrogen storage properties of V55Ti22.5Cr16.1Fe6.4 BCC alloy were researched by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), energy dispersive Xray spectrometer (EDS) and pressure-composition-temperature (PCT) measurements. An obvious segregation of Ce happens in the Ce-containing alloys, and the addition of Ce did not change the structure of BCC alloy and the lattice parameter. The activation performance of V55Ti22.5Cr16.1Fe6.4 is improved greatly by the addition of Ce. The Ce-free alloy cannot absorb hydrogen without being activated under a high temperature, but all Ce-containing alloys can absorb hydrogen rapidly at room-temperature. The absorption and desorption hydrogen capacities and the plateau pressures have no evident change when Cc content increases. Both Ce and CeO2 were found in the Ce-containing alloys. It was due to the high activation property of Ce, which can react with hydrogen, that the Ce-containing alloys are activated rapidly. (c) 2006 Elsevier B.V. All rights reserved.