A carbon monoxide oxidation device for oxidizing carbon monoxide contained in a hydrogen rich reformat gas includes a gas stream perturbation device designed as at least one propeller-shaped plate with a plate portion having a surface facing the gas stream and at least one blade which is connected to the plate portion and has a leading edge and an effluent edge, wherein a surface defined between leading edge and effluent edge is inclined in relation to the surface of the plate portion with a predetermined blade inclination angle, thereby defining at least one opening in the plate.