N-doped hollow carbon nanospheres embedded in N-doped graphene loaded with palladium nanoparticles as an efficient electrocatalyst for formic acid oxidation

• Pd/NHCN@NG catalyst exhibits 4.21 times higher activity than commercial Pd/C for formic acid oxidation. • The 3D porous structure with N-doping enhances catalytic active surface area and CO poisoning resistance. • The simple and economical synthesis method offers a scalable approach for high-performance fuel cell catalysts. • The study provides a strategy for designing advanced carbon-based support materials for electrocatalysts.