Fuel cells are electrochemical energy instruments that convert chemical energy of a fuel and oxygen to electricity. The use of metal nanoparticles and their composites offers many attractive avenues for oxygen reduction reactions (ORR)[1]. Particularly, noble metals like platinum [2], palladium [3], and ruthenium [4] have been extensively reported for electrocatalytic applications [1]. However, their widespread applications are severely hindered by the element scarcity, expensiveness, and poor long-term stability[5]. therefore, it is imperative to develop highly active ORR electrocatalysts with earth-abundant and cost-effective components[5].
