The invention relates to a micro-reactor for carrying out at least one catalytic reaction between two or more reactants in each case, comprising a stacking sequence of reaction surfaces (1) for carrying out at least one exothermic reaction, and a cooling region (6) divided at least into individual fields (6) with feed and discharge devices for the coolant.

The invention relates to a micro-reactor for carrying out at least one catalytic reaction between two or more reactants in each case, comprising a stacking sequence of reaction surfaces (1) for carrying out at least one exothermic reaction, and a cooling region (6) divided at least into individual fields (6) with feed and discharge devices for the coolant.

A reaction assembly has an elongate vessel defining a reaction chamber. Planar supports within the reaction chamber have surfaces for supporting a solid catalyst. The planar supports are mounted transversely to an elongate axis of the vessel, forming a series of spaced-apart barriers. A conduit introduces gas through openings between successive barriers such that gas flow through the conduit causes gas to flow along the support surfaces. With selection of an appropriate metal nanoparticle catalyst that may be seeded on the support surfaces. the reaction assembly may be used to produce carbon nanofibers from carbon monoxide and hydrogen, wherein the nanofibers may be subsequently removed via injection of a fluid.