NiCo2O4 spinel/ordered mesoporous carbons as noble-metal free electrocatalysts for oxygen reduction reaction and the influence of structure of catalyst support on the electrochemical activity of NiCo2O4

Three ordered mesoporous carbons (OMCs) with different structures are used as catalyst supports for growth of NiCo 2 O 4 spinel. The high surface area of OMCs provides more active sites to adsorb metal precursors . The porous structure confines the growth of NiCo 2 O 4 and supplies more efficient transport passage for reactant molecules to access the active sites. Due to the structural characteristics of OMCs and catalytic properties of NiCo 2 O 4 , NiCo 2 O 4 /OMCs composites are highly active, cheap, and selective noble metal-free electrocatalysts for the oxygen reduction reaction (ORR) in alkaline solution. The electrochemical activity of NiCo 2 O 4 supported on three OMCs with different structures, surface areas, pore sizes, pore volumes , and defective sites is studied. NiCo 2 O 4 /OMCs composites may be further used as efficient and inexpensive noble metal-free ORR catalysts in alkaline solution.