Abstract
Commercial interest in Pt and Pt-based catalysts is hindered by their high cost. Herein, we have synthesized {111} faceted rice-grain like nanoparticles of p-MnWO 4 with wolframite structure by a polyol method, and applied as catalysts for the ORR in alkaline electrolyte. It enabled a transfer of electron from t 2g orbital of Mn 3d to the empty antibonding orbital of W 5d, producing plentiful Mn3+ 3 + states towards ORR. Moreover, it showed superior ORR activity to CoWO4 4 and FeWO4 4 prepared similarly, and to a h-MnWO 4 prepared by a hydrothermal procedure. p-MnWO 4 exhibited lowest negative onset potential (0.92 V vs RHE) and smallest Tafel slope (50 mV dec-1). -1 ). Moreover, it achieved highest redox reaction mediated current density (-4.2 mA cm-2 ), attributable to Mn3+ 3 + to Mn2+ 2 + reduction and promising stability (96.6 %) over 6 h Excellent performance of p-MnWO 4 is associated with optimal O2 2 adsorption energies caused by metal to metal charge transfer and {111} faceted rice- grain like p-MnWO 4 nanoparticles.