TY - JOUR A1 - Bernicke, M. A1 - Ortel, Erik A1 - Reier, T. A1 - Bergmann, A. A1 - De Araujo, J.F. A1 - Strasser, P. A1 - Kraehnert, R. T1 - Iridium oxide coatings with templated porosity as highly active oxygen evolution catalysts: Structure-activity relationships N2 - Iridium oxide is the catalytic material with the highest stability in the oxygen evolution reaction (OER) performed under acidic conditions. However, its high cost and limited availability demand that IrO2 is utilized as efficiently as possible. We report the synthesis and OER performance of highly active mesoporous IrO2 catalysts with optimized surface area, intrinsic activity, and pore accessibility. Catalytic layers with controlled pore size were obtained by soft-templating with micelles formed from amphiphilic block copolymers poly(ethylene oxide)-b-poly(butadiene)-b-poly(ethylene oxide). A systematic study on the influence of the calcination temperature and film thickness on the morphology, phase composition, accessible surface area, and OER activity reveals that the catalytic performance is controlled by at least two independent factors, that is, accessible surface area and intrinsic activity per accessible site. Catalysts with lower crystallinity show higher intrinsic activity. The catalyst surface area increases linearly with film thickness. As a result of the templated mesopores, the pore surface remains fully active and accessible even for thick IrO2 films. Even the most active multilayer catalyst does not show signs of transport limitations at current densities as high as 75 mA cm-2. KW - Electrochemistry KW - Iridium KW - Structure–activity relationships KW - Template synthesis KW - Water splitting PY - 2015 U6 - https://doi.org/10.1002/cssc.201402988 SN - 1864-5631 SN - 1864-564X VL - 8 IS - 11 SP - 1908 EP - 1915 PB - Wiley-VCH CY - Weinheim AN - OPUS4-33503 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -