Covalently grafted platinum nanoparticles to multi walled carbon nanotubes for enhanced electrocatalytic oxygen reduction

► Covalently grafting Pt to MWCNT via sulfur atom (MWCNT-S-Pt). ► Enhancement of the catalyst activity via covalent bonding. ► Better catalysis with reduced Pt use in MWCNT-S-Pt. ► Enhanced four electron ORR with minimal H2O2 production.