The Flower-like Co3O4 Hierarchical Microspheres for Methane Catalytic Oxidation

The development of non-noble Co3O4 catalysts exposing highly active crystal planes to low-temperature methane oxidation is still a challenge. Hence, a facile solvothermal method was adapted to construe flower-like Co3O4 hierarchical microspheres (Co3O4-FL), which are composed of nanosheets with dominantly exposed {112} crystal planes. The flower-like hierarchical structure not only promotes the desorption of high levels of active surface oxygen and enhances reducibility, but also facilitates an increase in lattice oxygen as the active species. As a result, Co3O4-FL catalysts offer improved methane oxidation, with a half methane conversion temperature (T50) of 380 °C (21,000 mL g−1 h−1), which is much lower than that of commercial Co3O4 catalysts (Co3O4-C). This study will provide guidance for non-noble metal catalyst design and preparation for methane oxidation and other oxidative reactions.