A device for the through-flow of a fluid may include a fluid inlet and a fluid outlet. A porous structure with interconnected pores is arranged between the fluid inlet and the fluid outlet, and the fluid inlet and the fluid outlet define an overall flow direction. The porous structure is coupled to a wall to provide for heat conduction between the porous structure and the wall. The porous structure has a porosity gradient along a first direction, which is cross to the overall flow direction. The porosity gradient develops along the first direction between a first porosity at a first location proximal to the wall and a second porosity larger than the first porosity at a second location remote from the wall. The difference between the second porosity and the first porosity may be at least 4%.