A stochastic modelling technique for simulating sintered titanium powder-based porous transport layers (PTLs) of the polymer electrolyte membrane (PEM) electrolyzer was developed and used to generate PTLs with varying structures and transport properties. Two stochastic parameters (seeding parameter and the filling radius) were introduced in the model to control the powder-based PTL structure. The seeding parameter was used to control the titanium particle packing density, whereby increasing the packing density led to smaller the mean pore and throat diameters. The filling radius was used to create and control the sinter neck and grain morphology. Larger filling radii resulted in larger mean pore and throat sizes. PTLs with larger pores and throats exhibited higher single-phase permeabilities. A representative PTL was numerically generated with a single-phase permeability that deviated from the commercial benchmark by only 2%. Specifically, this work can be used to inform state-of-the-art manufacturing procedures so that the spatial distribution of the particles and their sinter necks can be tailored to achieve prescribed transport properties for enhanced PEM electrolyzer performance. (C) 2019 The Electrochemical Society.