Essentially, H2O2 is partially produced from O2 through the ORR process on the cathode. O2 activation relies on metal site back-donation; higher back-donation yields two adsorbed oxygen, while lower levels fail to activate O2. Hence, optimizing backdonation of metal site is crucial for catalyst design to enhance H2O2 performance. The back-donation ability of metal site is closely related with metal-support interaction. In this vein, the intricate behavior is typically evaluated using the d-band center theory pioneered by J. K. Nørskov, which mainly gauges the electron orbital freedom between metal and support. However, for ferromagnetic support and paramagnetic metal site, where metal site-loading may alter the spin order population of magnetic support, the electronic properties associated with spin degree of freedom play a considerable role in metal-support interaction compared to d-band center.