To test our hypothesis about SCE in SACs, we chose OER and ORR as the reactions of interest because of their well-estabilished scaling relations and the associated difficulty of changing them. We used the metal-nitrogen-carbon (M-N-C) materials in which MN4 fragments are anchored in the plane of defected graphene as model SACs thanks to the ease of synthesis and their potential of being costeffective OER and ORR catalysts . Through periodic spin-polarized densityfunctional theory calculations, we found that SCE can disrupt the scaling relationships of OER and ORR in two ways: (1) SCE disrupt the scaling relation between ΔG*O and ΔG*OH (ΔG*O = 2ΔG*OH on the pure metal surface ); (2) SCE selectively stabilizes *OOH without strengthening the adsorption of *OH, which decreases the free energy change from *OH to *OOH (ΔG*OOH = ΔG*OH + 3.2 eV on the pure metal surface , and the ideal intercept is 2.46 eV). As a result, we obtained more favorable energetics of OER and ORR, which could convert into better turnover-frequencies, as supported by a microkinetics simulation. Our study demonstrates the significance of exploring the secondary coordination effects in heterogeneous SACs and leveraging them for enhanced catalytic performances. We first built 28 different types of M-N-C models (denoted as MN4/G) differing by the element of metal center (Figure ), some of which have been reported in both experimental and theoretical studies . Then the thermodynamic and electrochemical stabilities of these MN4/G structures were assessed by formation energy and dissolution potential . Those in the upper left zone of Figure (negative formation energy and positive dissolution potential) are energetically more favorable, covering many experimentally synthesized MN4/G SACs (M=Fe, Ni, Cu, Zn, Ru, Rh, Pd, and Ir) .