Fabrication of Tungsten Carbide Nanoparticle-encased Graphite-like Mesoporous Carbon as a Precious Metal-free Electrocatalyst for Oxygen Reduction

Tungsten carbide nanoparticle-encased graphite-like mesoporous carbon (WC/MG), as a precious metal- free cathode catalyst for oxygen reduction reaction, was successfully synthesized by a template replicating-assisted chemical vapor deposition (CVD) method. The obtained mesostructured WC/MG composite possesses high oxygen reduction reaction catalytic activity and stable electrochemical property. In O₂-staturated 0.1 mol/L KOH solution, the half-wave potential (E_1/2) and limiting current density of the sample WC/MG-900 annealed at 900℃ were only 50 mV and 0.2 mA/cm² lower than those of commercial Pt/C catalyst, respectively. Koutecky-Levich (K-L) plots and rotating ring-disk electrode (RDE) measurements indicated that the mesostructured WC/MG exhibited an approximate 4 e^- transfer pathway during the ORR process. The comparable ORR performance to Pt/C, long-lived electrochemical stability and excellent methanol tolerance make the synthesized mesostructured WC/MG composite a potential electrode catalyst in oxygen reduction reaction.