Acid etching induced defective Co3O4 as an efficient catalyst for methane combustion reaction

Development of an effective Co3O4 material as an advanced non-noble metal catalyst for methane combustion has great economic and environmental significance. Herein, a facile acid etching procedure is adapted to engineer a defective Co3O4 possessing both highly exposed surface defects and lattice defects such as abundant oxygen vacancies. The defective structures facilitate an elevated exposure of active surface oxygen and enhanced redox properties. Meanwhile, the acid treatment endows a more acidic surface, which will promote the desorption of the CO2 product. Consequently, an improved activity for methane combustion with a half methane conversion temperature (T50) of 311 °C (33 000 mL g−1 h−1) is obtained for the defective Co3O4, corresponding to the methane conversion rate of 4.1 μmol g−1 s−1, 5.2 times that of the pristine Co3O4. The universality of this strategy is further verified towards a MnO2 catalyst. This study will provide positive guidance for non-noble metal catalyst design in the application of methane combustion.