Magnetron sputtered Ir thin film on TiC-based support sublayer as low-loading anode catalyst for proton exchange membrane water electrolysis

•Ir was sputtered on TiC-based support sublayer, hot-pressed on anode side of PEM.•TiC-based support sublayer was capable of withstanding high anodic potentials.•PEMWE performances are comparable to state-of-the-art, high-loading catalysts.

Proton exchange membrane (PEM) water electrolysis (PEMWE) is getting more attention in recent years as a promising alternative in context of energy storage from renewables. However high prices of platinum and iridium, currently considered to be the state-of-the-art electrocatalysts, prevent wider commercialization of this technology. In this paper, we present unconventional and cost-effective preparation method of anode catalyst, containing low amount of noble metal. Thin Ir film is magnetron sputtered on TiC-based support sublayer, hot-pressed on anode side of Nafion® N115 PEM. Following three parameters were systematically varied and their impact on PEMWE in-cell performance was evaluated: total TiC-based support material loading on the PEM, ionomer content within the support sublayer and Ir catalyst loading on top of the support sublayer. In addition, TiC-based sublayer underwent accelerated aging procedure, followed by photoelectron spectral analysis to prove its ability to withstand high anodic potentials. Remarkable PEMWE in-cell performances were obtained, considering amount of used Ir; 1.74 V (with ∼80 μg cm−2 of Ir), 1.72 V (with ∼160 μg cm−2 of Ir) and 1.71 V (with ∼240 μg cm−2 of Ir) at 1 A cm−2 and 80 °C.

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