Construction of a catalyst using activated manganese ore and Co3O4 for efficient catalytic combustion of ethane†

Natural manganese ore (NMO) has received extensive attention on account of its inherent stability, abundant reserves, and low cost. The higher specific surface area and abundant active sites are considered crucial for catalytic combustion. However, owing to the limited specific surface area inherent to natural manganese ore, we employed an acid etching activation treatment to enlarge the specific surface area of NMO (from 17.8 m² g⁻¹ to 48.9 m² g⁻¹). Herein, we successfully fabricated composite catalysts consisting of activated natural manganese ore (HNMO) and Co₃O₄ using the ethylene glycol sol–gel method and then evaluated them for the catalytic combustion of ethane. Results showed that the catalytic performance of the composite catalysts for ethane could not be enhanced monotonically by increasing the introduction of Co indiscriminately. Among them, the Co₂-HNMO catalyst exhibited a higher specific surface area, increased Mn⁴⁺ and Co³⁺ contents and higher oxygen mobility, which were attributed to the significant interaction between Co₃O₄ and HNMO. The T₉₀ of the corresponding Co₂-HNMO catalyst was 294 °C under a space velocity of 40 000 mL g⁻¹ h⁻¹. This work presents new insights into the design and synthesis of efficient composite catalysts based on natural minerals.