The perovskites were tested in CO oxidation in an automated reactor according to a standard operating procedure. We assessed the catalytic performance by analyzing the temperature required to reach 10% CO conversion, hereafter denoted ? @A (Table ). The value of ? @A reflects the activity, and the lower the ? @A , the higher the activity. The ? @A values are in the range [116, 435] °C, showing that the considered training set of perovskites present remarkably diverse activity. The ? @A generally depends on the B element and increases in the following order: Co < Mn < Fe < Cr. However, there are exceptions, e.g., ? @A BCD=) E < ? @A BCFG) E or ? @A HIJK) E < ? @A L=DM) E . The least and most active materials of the 13 perovskites in the training set are PrCrO3 and LaCoO3, respectively, with ? @A values of 435 and 116 °C, respectively.