From the 60 SAA surface sites considered in the screening, 23 fulfill the propositions in σ selected . We performed new DFT-mBEEF calculations to confirm whether the SAAs selected by the SG rules indeed provide significant C-O bond elongation in chemisorbed CO 2 . The computational settings for these geometry optimizations were similar to the ones described in Sec. II A. We evaluated the 23 systems selected by the SG rules. These results are displayed in the upper half of Figure . In this figure, the orange bins correspond to the distribution of ∆d C-O max values for the 23 systems. 21 of the 23 tested adsorption sites activate CO 2 . These systems contain the SA elements Y, Zr, Nb, Mo, Hf, Ta, W, and Re on the Cu(110) surface, the SA elements Y, Nb, Mo, Ta, W, and Re on the Zn(0001) surface, and the SA elements Y, Zr, Nb, Mo, Hf, Ta, and Re on the Pd(100) surface. The average ∆d C-O max among these 23 sites is equal to 0.139 Å. The system displaying the largest elongation among the tested sites is Hf@Cu(110) (∆d C-O max = 0.235 Å). This large bond elongation is closer to the maximum value within the training data set, of 0.252 Å, which is associated to a long bridge in an Os@Cu(110) surface. Two sites selected by the SG rules do not activate CO 2 (Zr@Zn(0001) and Hf@Zn(0001)). Additionally, we also use DFT-mBEEF to evaluate CO 2 activation TABLE III. Host surfaces and bridge sites considered in the screening of SA and DA alloys suitable for CO 2 activation. In the case of the SAAs, we used the 20 SAs highlighted in yellow in Fig. . For DAAs, we used the set of 33 atoms highlighted in Fig. (green and yellow), and r d-SA in σ selected is taken as the average of the two substituted atoms. Applying the rules allows a reduction of 62% and 75% of the candidate surface sites in the considered SA and DA alloys, respectively. Moreover, additional DFT-mBEEF calculations confirmed the rules' capability to predict an effective CO 2 activation. max among these 15 systems is 0.178 Å, lower than the corresponding value among the selected SAA surface sites (0.235 Å). Overall, σ selected provides good criteria to identify sites where CO 2 can be activated in SAAs.