TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The first ratio amounts to 48:52. The second ratio amounts to 51:49. The intermetallic compound of tungsten and iridium exhibits an ordered atomic configuration of tungsten- and iridium atoms. An X-ray diffraction profile of the intermetallic compound of tungsten and iridium, exhibits at least one peak which is not present in X-ray diffraction profile of atomic tungsten or iridium. The X-ray diffraction profile of the intermetallic compound of tungsten and iridium, exhibits a peak at 2 theta of 33-41 and/or a peak at 2 theta of 23-31. The peak at 2 theta of 33-41, exhibits a relative intensity of 42-50% compared to the peak at 2 theta of 39-47 having a relative intensity of 100%. The peak at 2 theta of 23-31, exhibits a relative intensity of 31-39% compared to the peak at 2 theta of 39-47 having a relative intensity of 100%.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The specific activity of the combination of the substrate and the catalyst is 2400-3600 mu A/cm2. The substrate comprises a substrate surface and a substrate thickness, where the ratio of the substrate thickness and circumference of the substrate surface is less than 0.01:1. The catalyst comprises a catalyst surface and a catalyst thickness, where the ratio of the catalyst thickness and circumference of the catalyst surface is less than 0.01:1. The substrate exhibits a thickness of 10-50 nm. The ratio of the substrate thickness and the catalyst thickness is 2:1-10:1. The substrate comprises not less than 90 wt.% tungsten and iridium. The catalyst device further comprises a base, where the substrate is arranged between the base and the catalyst. The base comprises a gas diffusion layer made of vitreous- and graphitized carbon, silicon dioxide, carbon fiber, ceramic, plastic, impact-resistant plastic, glass, toughened glass, lava and/or glazed lava. Preferred Method: The step (a) comprises sputtering of iridium and tungsten on the base for forming the intermetallic compound of tungsten and iridium. The sputtering is carried out at a temperature of less than or equal to 700 degrees C.