Abstract: A liquid/gas diffusion layer (LGDL) 112 for use in a proton exchange membrane electrolyzer cell 100 includes a planar body 120 having first and second surfaces 128, 130 that are separated by a body thickness 126. The body defines 120 a plurality of straight-through, non-interconnected, pores 122 extending through the body thickness 126, between the first and the second surfaces 128, 130. Each pore 122 has a peripheral rim shape 124, a throat area, and is separated from one another by a land length distance. The body has a porosity c that is calculated by dividing a total throat area of the plurality of pores AP by a total surface area of the surface around the pores AH, and where the porosity ratio e is between approximately 0.20 and approximately 0.80.