Fluorine doped (Ir,Sn,Nb)O2 anode electro-catalyst for oxygen evolution via PEM based water electrolysis

• Nanostructured (Ir,Sn,Nb)O2:F thin films have been wet chemically synthesized.
• (Ir0.30Sn0.35Nb0.35)O2:10F films exhibit similar activity to IrO2.
• (Ir0.30Sn0.35Nb0.35)O2:F thin films exhibits durability comparable to pure IrO2.
• (Ir,Sn,Nb)O2:F thin films are promising OER electro-catalysts.

A solid solution of fluorine combined with IrO2, SnO2 and NbO2, denoted as (Ir,Sn,Nb)O2:F, corresponding to composition (Ir0.30Sn0.35Nb0.35)O2:x wt.% F, where x ranges from 0 to 20 was coated on a pretreated Ti foil by decomposition of a homogeneous mixture of Ir, Sn, Nb and F precursors. The (Ir,Sn,Nb)O2:F thin film compositions have been studied as promising anode electro-catalysts for PEM based water electrolysis. Results suggest that (Sn,Nb)O2:F solid solution is a novel support material for IrO2 electro-catalyst. Furthermore, it has been identified that a reduction of IrO2 content up to 70 mol.% shows better electrochemical activity compared to pure IrO2 with F doping. This excellent electrochemical activity during water electrolysis has also been supported by long term durability studies of (Ir,Sn,Nb)O2:F thin films. These results have also been corroborated using first-principles calculations of the total energies, electronic structures and cohesive energies of the model systems.