Synergistic promotion effect of MgO and CeO₂ on nanofibrous Ni/Al₂O₃ catalysts for methane partial oxidation

Ni/Al₂O₃ catalysts are formed via NiAl₂O₄ reduction while inactive NiAl₂O₄ is readily re-formed in the presence of oxidant agent during reactions, such as oxygen in methane partial oxidation. MgO has demonstrated promotion effect through securing Al₂O₃ to form MgAl₂O₄ during catalyst calcination so as to diminish NiAl₂O₄ formation. However, the promotion effect is limited by the formation of NiO-MgO solid solution with low reducibility. CeO₂ promotes NiAl₂O₄ reduction via forming CeAlO₃ and therefore prevents NiAl₂O₄ re-formation during the reaction. This study, for the first time, demonstrates the synergistic promotion effect of MgO and CeO₂ on the Ni/Al₂O₃ catalysts for methane partial oxidation through optimizing MgO and CeO₂ contents in the MgO-CeO₂-Ni/Al₂O₃ catalyst system. The thermally stable structure of fibrous catalysts prepared by one-step electrospinning enables the investigation of the synergistic promotion.