MoFe/Beta@CeO2 core-shell catalyst has been controllably synthesized by a self-assembly method. MoFe/Beta@CeO2 shows a remarkable improvement of deNOx activity, excellent SO2 and H2O tolerance and high thermal stability. CeO2 sheaths have inhibited the generation of ammonium sulfate and nitrate species from blocking the active sites. CeO2 shells have served as an effective barrier to prevent the aggregation of metal oxide NPs. The CeO2 shells promote the formation of nitrites species and NO oxidation to NO2.