Facile synthesis of MoxC-FeNi@NC with an OER activity superior to RuO2 and IrO2/C.

The design of efficient, non-precious metal electrocatalysts is still the hot topic for water oxidation. However, the reported transition metal-based electrocatalysts usually exhibit far lower activity, compared with precious metals. In this work, we report the excellent oxygen evolution reaction (OER) performance of Mo x C-FeNi@ NC (NC, nitrogen-doped carbon) by a simple pyrolytic method. To reach the current density of 10 mA cm−2, Mo x C-FeNi@NC only needs a low overpotential of 306 mV. Surprisingly, the Mo x C-FeNi@NC even showed lower overpotential than those of noble metal oxides, e.g. RuO 2 (~320 mV), IrO 2 /C (360 mV). The excellent OER activity is mainly ascribed to the unique FeNi electron configuration, efficient electron transfer and higher surface area. Compared with FeCo and CoNi, FeNi alloy possesses half-filling *π3d electron configuration, leading to suitable adsorption for OH−; and Mo x C has effectively improved electrical conductance of Mo x C-FeNi@NC, thus greatly improving the OER reaction kinetics. This work provides an earth-abundant, efficient electrocatalyst for water oxidation. Image 1 • Mo x C-alloy@NC shows a lower overpotential than RuO 2 and IrO 2 /C. • The half-filling *π3d orbit of FeNi favors for appropriate adsorption for OH−. • The improved electrical conductance by Mo x C improves OER kinetics. • This work provides an efficient, earth-abundant electrocatalyst for water oxidation. [ABSTRACT FROM AUTHOR]