Cex-MnCoAlOx composite metal oxide catalyst as well as preparation method and application thereof

The invention discloses a Cex-MnCoAlOx composite metal oxide catalyst which exists in the form of a crystal phase, wherein Al2O3 and CoAl2O4 phases are mainly used in the catalyst. The preparation method comprises the following steps: (1) mixing cobalt nitrate, aluminum nitrate and urea, adding a manganese nitrate solution, carrying out constant-temperature treatment, washing, drying, grinding and calcining; and (2) adding cerous nitrate and stronger ammonia water, and carrying out constant-temperature treatment, centrifugation, washing, drying and calcination. According to the invention, the Cex-MnCoAlOx catalyst is prepared by a two-step solvothermal compounding method, and the obtained catalyst has high SO2 and NOx resistance, good dispersity and relatively high purity; by changing the molar weight of cerium, the substances can be better polymerized together, the interaction among the metals is more favorable for improving the catalytic performance, and a larger specific surface area can be obtained, so th