A Highly Efficient Co3O4 Nanoparticle-Incorporated Mesoporous Beta Composite as a Synergistic Catalyst for Oxygen Reduction

Cost-efficient and high-performance oxygen reduction electro-catalysts are widely pursued to boost the sluggish oxygen reduction reaction (ORR) for renewable-energy technology applications. Here, a novel precious-metal-free cathode catalyst, Co3O4 nanoparticle-incorporated mesoporous Beta zeolite, was first synthesized by using a facile steam-assisted crystallization (SAC) and hydrothermal approach. Owning to the synergetic catalytic effects between the Co3O4 nanoparticles and the mesoporous Beta matrix, the resulting Co3O4/m-Beta nanocomposites catalyst showed comparable ORR electrochemical catalytic activity to the benchmark 20 wt% Pt/C catalyst with a high onset potential of 0.88 V, and much higher methanol tolerance with a negligible negative shift of the peak potential and excellent electrochemical stability in alkaline media. The relatively higher surface Co2+ concentration and the abundant Bronsted acid sites facilitate the ORR process, mainly through a 4e(-) pathway, which makes the Co3O4/m-Beta nanocomposite a favorable candidate for improving energy storage and conversion efficiencies in fuel cells.