Manganese Oxide Nanorod-Decorated Mesoporous ZSM-5 Composite as a Precious-Metal-Free Electrode Catalyst for Oxygen Reduction

A precious-metal-free cathode catalyst, MnO2 nanorod-decorated mesoporous ZSM-5 zeolite nanocomposite (MnO2/m-ZSM-5), has been successfully synthesized by a hydrothermal and electrostatic interaction approach for efficient electro-chemical catalysis of the oxygen reduction reaction (ORR). The active MnOOH species, that is, Mn4+/Mn3+ redox couple and Bronsted acid sites on the mesoporous ZSM-5 matrix facilitate an approximately 4e(-) process for the catalysis of the ORR comparable to commercial 20 wt% Pt/C. Stable electrocatalytic activity with 90% current retention after 5000 cycles, and more importantly, excellent methanol tolerance is observed. Synergetic catalytic effects between the MnO2 nanorods and the mesoporous ZSM-5 matrix are proposed to account for the high electrochemical catalytic performance.