Previous calculations utilized the widely employed CHE model in electrocatalysis simulations, known for its simplicity yet significant success in elucidating reaction mechanisms and predicting ORR catalysts. However, the model falls short in accurately accounting for the effect of applied potentials on catalytic properties due to the fixed electron number with conventional canonical-ensemble algorithm, resulting in the inaccurate description in the effect of pH and electrode potential on free energy. To address this issue, electrocatalysis simulations under the applied potential were carried out using a uniform charge background to compensate the surface excess charges . The most stable or highest ORR catalytic activity magnetic states of the three catalysts were taken into account as depicted in Figure .