Hydrogen spillover and structural defects in a PdO/zirconia nanophase synthesized through a surfactant-templated route

Nanosized zirconia with structural defects was synthesized by using surfactant-templated method. The average crystallite size, phase composition, cationic defect concentration and structural microstrain in the monoclinic phase of zirconia annealed at 800 °C were quantitatively determined by the Rietveld refinement. An unusual behaviour of hydrogen reversibly storing into/releasing from the PdO/ZrO 2 nanophases was observed, which related to formation/decomposition of a hydride phase β-PdH 0.76 and to hydrogen storage in the cationic defects of zirconia nanophases by means of hydrogen spillover from Pd metals to zirconia support.