A novel Ce(0.8)Fe(0.1)Zr(0.1)O(2) solid solution with high catalytic activity for hydrogen storage in MgH(2)

The effect of the solid solution Ce(0.8)Fe(0.1)Zr(0.1)O(2), successfully prepared by a hydrothermal synthesis method, on the hydrogen sorption properties of MgH(2) is systemically investigated. The Ce(0.8)Fe(0.1)Zr(0.1)O(2)-modified MgH(2) composite exhibits remarkable hydrogen kinetics properties and thermodynamics behavior compared to those of as-milled MgH(2), with a reduction in the initial desorption temperature of approximately 82 K. With respect to the hydrogen kinetics, the Ce(0.8)Fe(0.1)Zr(0.1)O(2)-added sample could uptake approximately 5.3 wt% H(2) at 473 K in 2500 s, whereas only 1.5 wt% hydrogen could be absorbed by pristine MgH(2) in the same conditions. Furthermore, about 4.5 wt% of hydrogen could be desorbed by Ce(0.8)Fe(0.1)Zr(0.1)O(2)-doped MgH(2) composite at 623 K, which was 2 wt% higher than the as-milled MgH(2) sample over the same period of time. The decomposition apparent activation energy for MgH(2)–Ce(0.8)Fe(0.1)Zr(0.1)O(2) is reduced to 84.3 kJ mol(−1), which is about 77 kJ mol(−1) lower than that of pristine MgH(2). It is believed that the notable improvement in the hydrogen sorption kinetics is due to the in situ-formed active species of CeH(2.51) and MgO as well as the abundant oxygen vacancies, which play a vital role in catalyzing the hydrogen sorption performance of MgH(2).