3D Ni Redox-active metal-organic framework based on ferrocenyldiphosphinate and 4,4′-bipyridine ligands as an electrocatalyst for the oxygen reduction reaction in proton-exchange membrane fuel cells.

The three-dimensional Ni redox-active metal-organic framework [Ni(bpy)(fcdHp)] based on nickel(ii) cations, anions of ferrocenylbis(H-phosphinic) acid (H2fcdHp), and 4,4′-bipyridine (bpy) was first tested as an oxygen reduction reaction (ORR) catalyst. This compound showed remarkable efficiency and good stability under electrochemical conditions. The diagnostic performance in a proton-exchange membrane fuel cell with this catalyst on the cathode side of the membrane-electrode assembly (MEA) was evaluated for the first time. The catalytic ability of the new system as an ORR catalyst without a platinum catalyst on the anode side was confirmed in a half-cell setup, in which the cathode compartment of the MEA and the anode (liquid electrochemical cell) are separated by a polyelectrolyte membrane. [ABSTRACT FROM AUTHOR]