Hybridization of Binary Non-Precious-Metal Nanoparticles with d-Ti3C2 MXene for Catalyzing the Oxygen Reduction Reaction

In this work, an advanced integrated electrode for high-performance electrocatalytic oxygen reduction is designed and fabricated directly by in-situ hybridization of binary non-precious metal (Fe-Co) ethylenediamine chelate complexes with multi-layered d-Ti3C2 MXene nanoflakes, in the formation of FeCo (3 : 1)-N-d-Ti3C2 MXene. The catalyst exhibits outstanding oxygen reduction reaction activity with more positive onset potential and half-wave potential than commercial 20 wt.% Pt/C and achieves a current density of 5.60 mA.cm(-2) in O-2-saturated 0.1 M KOH electrolyte solution. Furthermore, remarkable stability and methanol tolerance can be detected. The outstanding activity and stability can be attributed to the fact that the FeCoEDA chelate nanoparticles are successfully grafted onto the d-Ti3C2 MXene nanoflake substrate instead of being deposited. Thus, aggregation of the particles is prevented and a large specific surface area is provided, enhancing charge transfer reactions. We conclude that the in-situ hybridization of MXenes with non-precious metal compounds is a promising candidate for replacing traditional Pt-based catalyst materials for oxygen reduction in fuel cells.