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

Cost-efficient and high-performance oxygen reduction electrocatalysts 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 Brønsted 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.