Catalyst slurry with free radical scavenging function as well as preparation method and application of catalyst slurry

The invention relates to the field of proton exchange membrane fuel cells, in particular to catalyst slurry with a free radical scavenging function and a preparation method and application thereof, and the preparation method comprises the following steps: S1, preparing catalyst slurry A in a slurry bottle; s2, nanoscale CeO2, Ce2O3 and MnO2 are prepared into a mixture A according to the proportion of 1: 1: 1, then the mixture A is added into the catalyst slurry A, a mixture B is prepared, and the content of the added mixture A in the mixture B is 1%-5%; s3, the slurry bottle containing the mixture B is placed on a magnetic stirrer to be stirred for 10 min till even mixing is achieved, and a mixture C is formed; and S4, the slurry bottle containing the mixture C is placed on a homogeneous dispersion machine to be dispersed at a high speed, so that catalyst slurry B containing CeO2, Ce2O3 and MnO2 is obtained, and the catalyst slurry B is the required catalyst slurry with the free radical scavenging function. P