Process for manufacturing a porous alumina membrane for fuel cells

A Process for manufacturing a porous body, in particular suitable as a membrane, e.g. for use in a fuel cell, is described. To provide membranes with high inertia having high porosity and big pore diameters the process comprises the following steps: a) providing a thin substrate having the geometrical base of the body which is to be produced, b) providing an alumina film by an electrochemical process on the substrate, c) separation of the substrate from the alumina film and d) drying and chemical etching of the alumina film, wherein the substrate used is made of recrystallized material. Further, membranes produced with this process are described.