Optimized anode catalyst layer design for proton exchange membrane water electrolyzers using pore network modeling

Refining the pore architecture of the catalyst layer (CL) with fast mass transport dynamics in proton exchange membrane water electrolyzers (PEMWE) is essential for efficient hydrogen production. Herein, a pore network model is introduced for high-performance anode CL design in PEMWE. The design incorporates a tri-layer gradient CL structure, each layer characterized by distinct pore size distributions and porosity gradients, into a two-dimensional, two-phase, non-isothermal PEMWE model. The study reveals that, compared with uniform CL having mean pore diameter of 203 nm and porosity of 0.35, orienting the CL with progressively smaller pore diameters and higher porosity from the porous transport layer toward the proton exchange membrane improves current density by 5.3% at high operating voltage of 2.4 V. Additionally, the effect of pore configuration on saturation uniformity under different operational conditions were also explored. These insights provide important guidance for engineering advanced CL structures to boost PEMWE efficiency, thereby driving the efficient hydrogen production.