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Abstract: Carbon-supported IrO2 and RuO2 were prepared using an incipient wetness method and were then calcinated at various temperatures. IrO2/C and RuO2/C are less expensive than the conventional Pt/C material and more stable than metal Ni in an acidic electrolyte. Moreover, IrO2/C and RuO2/C are not influenced by under potential deposition (UPD) and show lower sensitivity to poisoning by Ni or Fe impurities. The physical properties of IrO2/C and RuO2/C were investigated via XRD and TEM. Cyclic voltammograms (CV) and Tafel plots were used to provide information regarding surface redox reaction and electrocatalytic activity. The activity and durability of IrO2/C and RuO2/C were studied after prolonged potential cycling between −0.3 and 0.3VSCE. After comparison of Tafel plots of Pt/C and IrO2/C after activation, it was observed that they have similar electrocatalytic activities in a hydrogen evolution reaction (HER). A single cell test with solid polymer electrolyte (SPE) proved that the performance of IrO2/C (0.5mgcm−2) was similar to that of Pt/C (0.5mgcm−2). [Copyright &y& Elsevier]

Abstract: Electrocatalysts of the general formula Ir x Ru1−x O2 were prepared using Adams’ fusion method. The crystallite characterization was examined via XRD, and the electrochemical properties were examined via cyclic voltammetry (CV) in, linear sweep voltammetry (LSV) and chronopotentiometry measurements in 0.5M H2SO4. The electrocatalysts were applied to a membrane electrode assembly (MEA) and studied in situ in an electrolysis cell through electrochemical impedance spectroscopy (EIS) and stationary current density–potential relations were investigated. The Ir x Ru1−x O2 (x =0.2, 0.4, 0.6) compounds were found to be more active than pure IrO2 and more stable than pure RuO2. The most active electrocatalyst obtained had a composition of Ir0.2Ru0.8O2. With an Ir0.2Ru0.8O2 anode, a 28.4% Pt/C cathode and the total noble metal loading of 1.7mgcm−2, the potential of water electrolysis was 1.622V at 1Acm−2 and 80°C. [Copyright &y& Elsevier]

Abstract: A novel anodic electrocatalyst Ir0.4Ru0.6Mo x O y for solid polymer electrolyte (SPE) water electrolysis is prepared by the modified Adams'' fusion method. The XRD, ICP, and BET are employed to determine the physical characteristics of Ir0.4Ru0.6Mo x O y and Ir0.4Ru0.6O2, and the electrochemical properties of the electrocatalysts are examined by cyclic voltammetry (CV) in 0.5M H2SO4. The results show that Ir0.4Ru0.6Mo x O y has much smaller particle size, larger specific surface areas and active surface area compared with Ir0.4Ru0.6O2. The results of single cell performance and the electrochemical impedance spectroscopy (EIS) tests also prove that Ir0.4Ru0.6Mo x O y has higher performance than Ir0.4Ru0.6O2. [Copyright &y& Elsevier]