High-performance CoxM3-xAlOy (M Ni, Mn) catalysts derived from microwave-assisted synthesis of hydrotalcite precursors for methane catalytic combustion

Abstract

The Co 2 Ni 1 AlO y -MW catalyst exhibited higher catalytic performance and the temperature required to achieve a methane conversion of 90% (T 90 ) was about 473 °C, this temperature was 40 °C lower than that on the NiO-IWI/Co 3 AlO y sample. The enhanced catalytic activity was correlated with higher surface area, better redox property, higher ratio of surface Co 3+ /Co 2+ species and surface absorbed oxygen and lattice oxygen (O ads /O latt ) derived from the synergistic effect over Co 2 Ni 1 AlO y -MW catalysts. • Mesoporous Co x M 3-x AlO y catalysts were prepared by the microwave method. • The nickel salt introduced illustrated the better impact on methane catalytic combustion performance. • There was a higher ratio of surface absorbed oxygen over the lattice oxygen for Co 2 Ni 1 AlO y -MW sample. A series of mesoporous Co x M 3-x AlO y (M Ni, Mn) catalysts have been obtained by calcination of layered double hydroxide (LDH) precursors prepared by the microwave method, the catalysts exhibited high activity for methane catalytic combustion. By changing the preparation method and type of metal salt introduced (Ni and Mn), it is effective for controlling the structure properties and reducibility of catalyst as well as the catalytic performance for the methane catalytic combustion. The Co 2 Ni 1 AlO y catalyst exhibited higher catalytic performance and the temperature required to achieve a methane conversion of 90% (T 90 ) was about 473 °C, this temperature was 40 °C lower than that on the NiO-IWI/Co 3 AlO y sample. The enhanced catalytic activity was correlated with higher surface area, better redox property, higher ratio of surface Co 3+ /Co 2+ species and surface absorbed oxygen and lattice oxygen (O ads /O latt ) derived from the synergistic effect over Co 2 Ni 1 AlO y catalyst. Therefore, the microwave method provided an effective path to develop the efficient combustion catalyst for higher performance.