A device D accommodated in a reactor R and containing a gas- and/or liquid-permeable bottom B, in the peripheral region of which is arranged a lateral boundary W which completely surrounds the bottom B and forms a volume V which is partially or completely filled with catalytic and/or non-catalytic moldings, there optionally being located on the side facing the bottom B in the upstream direction at least one noble metal and/or non-noble metal fabric, wherein a thermal insulation layer S is located on at least part of the surface of the inner side of the lateral boundary W of the device D, the material for the thermal insulation layer S being selected from the group consisting of ceramic material, microporous material and silicate fibers.