Direct observation of hydrogen spillover in Ni-loaded Pr-doped ceria

In situ studies on reduction processes in praseodymium-doped ceria and nickel-loaded doped ceria nanoparticles have been investigated using environmental transmission electron microscopy. The presence of pit-like defects on the oxide nanoparticles resulted in amorphization during reduction. Hydrogen-spillover in nickel-loaded praseodymium-doped ceria (PDC) was directly observed. Localized reduction of ceria in a H2 atmosphere was observed and attributed to gas–nickel–ceria interactions at the three-phase boundary. The spatial extent of the localized reduction zones was experimentally determined. The spillover mechanism is discussed in terms of surface diffusion properties of atomic hydrogen and oxygen species.

Figure optionsDownload high-quality image (407 K)Download as PowerPoint slideHighlights
► Reduction processes in Pr-doped ceria and Ni-loaded doped ceria nanoparticles.
► Pit-like defects give amorphization during reduction.
► Hydrogen-spillover in Ni-loaded Pr-doped ceria (PDC) was directly observed.
► The spatial extent of the localized reduction zones was experimentally determined.