Method for preparing flue gas SCR (Selective Catalytic Reduction) denitration catalyst

The invention relates to a method for preparing a flue gas SCR (Selective Catalytic Reduction) denitration catalyst. The method comprises the following steps of: mixing ammonium metavanadate, oxalic acid, manganese salt and water for preparing a mixture solution, adding titanium dioxide powder into the mixture solution, heating in water bath and stirring, and obtaining mixed sol by standing at room temperature; putting the mixed sol into a microwave oven, heating and drying by utilizing microwave radiation; and putting dried solid into a muffle furnace for burning. According to the method disclosed by the invention, a temperature window of the SCR catalyst can be broadened to a low-temperature direction, the problems of low denitration efficiency at low temperature and narrow temperature window of a commercial catalyst are solved; compared with the traditional drying method, the microwave radiation heating and drying method has the advantages that low-temperature SCR denitration activity of the composite catalyst can be increased to a large extend, when the activity temperature is up to 250 DEG C, the denitration efficiency of the catalyst prepared by the traditional drying method is up to 51.9%, and the denitration efficiency of the catalyst can be increased by 31.7 percentage points and can be up to 83.6% by the microwave radiation heating and drying method.