Nanostructured (Ir,Sn)O2:F – Oxygen Evolution Reaction Anode Electro-Catalyst Powders for PEM Based Water Electrolysis

Nanostructured powder catalysts comprising solid solutions of F doped SnO 2 and IrO 2 of different compositions were synthesized by a simple two step approach. High surface area SnO 2 :F was prepared initially using CTAB as a surfactant. (Ir,Sn)O 2 :F was then synthesized by forming a solid state solution with IrCl 4 and SnO 2 :F followed by heat-treatment in air at 400°C. The catalyst was then coated onto a porous Ti foil and has been studied as a promising anode electro-catalyst for oxygen evolution reaction (OER) in PEM based water electrolysis. The optimal composition of (Ir 0.3 Sn 0.7 )O 2 :10 wt% F displayed electrochemical activity comparable to the commercially available pure IrO 2 demonstrating ∼70 mol% reduction in noble metal content. The electrochemical stability tests also showed that (Ir,Sn)O 2 :F solid solution exhibits much better durability compared to commercial IrO 2 , the standard (OER) catalyst.