Synthesis of Ni-doped ceria nanoparticles and their unusual surface reduction in hydrogen

This work presents an original approach to preparing pure and Ni-doped CeO 2 nanoparticles (NPs) that can be directly drop-casted on a substrate or calcined to form powders.The reduction of the NPs in H 2 is very different than the one usually anticipated for supported NieCeO 2 catalysts.In situ soft X-ray absorption and infrared spectroscopies revealed that the reduction of Ce 4þ into Ce 3þ in H 2 proceeds via simultaneous oxidation of Ni 2þ ions into Ni dþ (2