Triblock polymer mediated synthesis of Ir-Sn oxide electrocatalysts for oxygen evolution reaction

Over the past several decades, tremendous effort has been put into developing cost-effective, highly active and durable electrocatalysts for oxygen evolution reaction (OER) in the proton exchange membrane water electrolyzer. This report explores an advanced and effective soft material-assistant method to fabricate Ir0.6Sn0.4O2 electrocatalysts with a 0.6/0.4 ratio of Ir/Sn in precursors. Adopting a series of characterization methods, the collective results suggest that the surfactant-material F127 content, as an important factor, can efficiently control the formation of Ir-Sn oxides with varying surface properties and morphologies, such as the grainy and rod-shaped structures. Associating with the half-cell and single electrolyzer, it is affirmed that the optimal ratio of (It + Sn)/F127 is 100 for the preparation of S100-Ir0.6Sn0.4O2 with obviously enhanced activity and sufficient durability under the electrolysis circumstances. The lowest cell voltages obtained at 80 degrees C are 1.631 V at 1000 mA cm(-2), and 1.820 V at 2000 mA cm(-2), when applying S100-Ir0.6Sn0.4O2 OER catalyst and Ti-material diffusion layer on the anode side and Nafion (R) 115 membrane. Furthermore, the noble-metal It loading in the same cell decreases to 0.77 mg cm(-2). These results highlight that Ir-Sn oxide synthesized by the soft-material method is a promising OER electrocatalyst. (C) 2013 Published by Elsevier B.V.