A method for sintering a porous coating on an open-structure substrate, i.e., a substrate with pre-made pores or openings. The open-structure substrate is spread with a coating paste that is prepared with such a viscosity so that the paste will not drip through the pores/openings on the open-structure substrate. The coating paste is then sintered to form a porous layer on the surface of the open-structure substrate. Optionally, the porous coating may be further coated with a catalyst for fuel cell applications.