Rational design of mesoporous NiFe-alloy-based hybrids for oxygen conversion electrocatalysis

Abstract

A mesoporous NiFe-based alloy was synthesized through a hard-template technique and investigated as the electrocatalyst for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Precious metal-free elements, i.e., nitrogen (N), nickel (Ni), and iron (Fe), were merged together through either doping or alloying to form a mesoporous structure supporting NiFe-alloy electrocatalyst (m-NiFe/CN_x). The synergetic effects from multiple active sites, in combination with structural merits, endowed the m-NiFe/CN_x electrocatalyst with an excellent electrocatalytic activity for both OER and ORR, including high activity, fast kinetics, modest overpotential, and excellent stability. The m-NiFe/CN_x also featured a simple and scalable synthesis process with a low cost, which makes it an attractive alternative catalyst to precious metal-based electrocatalysts for OER and ORR.