Robust Ni nanocatalysts formed by exsolution from nanofibrous fluorite ceramic supports for methane partial oxidation

Exsolution is a promising approach to prepare catalysts with both high metal catalyst dispersion and the strong metal/support interaction. Exsolved metal catalysts from conventional perovskite ceramics experience the limitation of reversible exsolution, which makes exsolved metal catalysts instable in the presence of oxidant, such as oxygen during methane partial oxidation (POM). This study has demonstrated stable Ni nanocatalysts exsolved from Y-doped ZrO₂ (YSZ) fluorite ceramic after NiO dissolution. The NiO dissolution was promoted through tuning Y-doping and elevating calcination temperature owing to the thermally-stable structure of fibrous catalysts. The robust Ni/YSZ catalysts generated a high methane conversion of about 79.5 % during the POM at 750 °C, which was stable during the test for 100 h owing to the stable Ni catalysts. Therefore, metal exsolution from fibrous fluorite ceramics represents an effective way to prepare efficient and stable nanocatalysts for catalytic redox reactions.