Biphasic intergrowth effects of La2MnNiO6–MgO composite oxide for methane catalytic combustion Original Research Article

Biphasic intergrowth La2MnNiO6–MgO composite oxide containing 30 wt% La2MnNiO6 was synthesized by ammonia aqueous (25 vol.%) co-precipitation method calcined at 1100 °C and investigated in the catalytic combustion of methane. Compared with the corresponding pure double perovskite-type oxide La2MnNiO6, the composite oxide La2MnNiO6–MgO exhibited much higher catalytic performance (T50 = 548 °C,T90 = 628 °C) and exceptional thermal stability. The excellent performance of La2MnNiO6–MgO was explained by various characterizations, such as XRD, ICP, H2-TPR, XPS, and TEM techniques. The catalytic activity of La2MnNiO6–MgO prepared by biphasic intergrowth method is superior to La2MnNiO6/MgO obtained by impregnation technique, mechanical mixing of La2MnNiO6 and MgO, and pure La2MnNiO6. The better performance of La2MnNiO6–MgO for methane catalytic combustion reaction is ascribed to a strong intergrowth interaction between La2MnNiO6 and MgO during the synthesis process. Therefore, the La2MnNiO6–MgO composite oxide can be deemed as an attractive candidate as a catalyst for the combustion of methane.