Hydrogen is gaining more and more attention because it is regarded as an important future fuel. Today, hydrogen is mainly produced from nonrenewable natural gas and petroleum. With concerns over worldwide energy demands and global climate change, alternative sources must be found. Obviously, water is recommended as the ideal source for the generation of large amounts of hydrogen.[1] In addition to electrolysis, recently several new processes, such as photovoltaic-photoelectrochemical water splitting [2][3][4] and one-step or multistep thermochemical water splitting [5,6] based on focused solar [7][8][9] or nuclear [10] heat, have been developed. Although water dissociation into oxygen and hydrogen is conceptually simple [Eq. (1)], efficient hydrogen productionfrom water remains difficult as a result of the low equilibrium constant of K p % 2 10 À8 at the relatively high temperature of 950 8C.

Hydrogen is gaining more and more attention because it is regarded as an important future fuel. Today, hydrogen is mainly produced from nonrenewable natural gas and petroleum. With concerns over worldwide energy demands and global climate change, alternative sources must be found. Obviously, water is recommended as the ideal source for the generation of large amounts of hydrogen.[1] In addition to electrolysis, recently several new processes, such as photovoltaic-photoelectrochemical water splitting [2][3][4] and one-step or multistep thermochemical water splitting [5,6] based on focused solar [7][8][9] or nuclear [10] heat, have been developed. Although water dissociation into oxygen and hydrogen is conceptually simple [Eq. (1)], efficient hydrogen productionfrom water remains difficult as a result of the low equilibrium constant of K p % 2 10 À8 at the relatively high temperature of 950 8C.

Mixed‐ion and electron‐conducting perovskite membranes are used to produce oxygen‐enriched air (see picture). These membranes are thermally and mechanically stable at high temperatures (>875 °C) over a long period of time, thus making them suitable for industrial processes. Oxygen concentrations of the enriched air typically reach 30–50 vol %.

Gemischtionische und elektronenleitende Perowskitmembranen werden zur Erzeugung sauerstoffangereicherter Luft eingesetzt (siehe Bild). Diese Membranen sind bei hohen Temperaturen (>875 °C) über lange Zeit thermisch und mechanisch stabil, was sie für industrielle Prozesse geeignet macht. Die Sauerstoffkonzentrationen der angereicherten Luft erreichen typische Werte von 30 bis 50 Vol.‐%.

Direct decomposition of N(2)O to N(2) using perovskite hollow fiber membranes is achieved by combination with in situ oxygen removal (see picture). A coupled partial methane oxidation allows N(2)-free synthesis gas to be obtained. This sustainable process combines N(2)O removal with the simultaneous production of valuable chemicals.