Abstract: The invention is directed to precious metal oxide catalysts, particularly to iridium oxide based catalysts for use as anode catalysts in PEM water electrolysis and other applications. The composite catalyst materials comprise iridium oxide (IrO2) and optionally ruthenium oxide (RuO2) in combination with an inorganic oxide (for example TiO2, Al2O3, ZrO2 and mixtures thereof). The inorganic oxide has a BET surface area in the range of 30 to 200 m2/g and is present in a quantity of 25 to 70 wt.-% based on the total weight of the catalyst. The catalyst materials are characterised by a good electrical conductivity >0.01 S/cm and high current density. The catalysts are used in electrodes, catalyst-coated membranes and membrane-electrode-assemblies for PEM electrolyzers, PEM fuel cells, regenerative fuel cells (RFC), sensors and other electrochemical devices.

Abstract: A ceramic microreactor for carrying out reactions having a large heat of reaction which has at least three interior spaces, with at least one interior space having internal buffers whose shape, number and positioning ensure homogeneous flow, is described. The microreactor is built up as a monolith from at least seven plate-shaped layers of inert ceramic material, preferably aluminium oxide, which form an upper heating/cooling space, a central reaction space and a lower heating/cooling space. One interior space has a coating of a catalyst comprising noble metal. The shape, number and positioning of the internal buffers is determined by means of flow simulation calculations; the internal buffers preferably have a lozenge shape. The microreactor displays very good selectivity in reactions having a large heat of reaction, in particular in heterogeneous gas-phase reactions, and is used in particular for hydrogen production and/or hydrogen purification in fuel cell technology.