An Investigation of morphological changes due to etching Ti porous transport layer via X-ray tomography for electrolyzer applications

Anodic porous transport layer (PTL) is a critical component for water/gas transportation to/from the anode catalyst layer and an important interface for electron/proton transfer in a proton exchange membrane electrolyzer cell. The common material used for PTL structure is Ti, which is highly prone to passivation in long-term application and can be degraded faster if it is not protected with a Pt coating. In order to deposit PTL with Pt, an etching procedure is required to remove formed TiO2 layer, resulting in huge morphological changes in this layer. The proposed study aims to investigate the morphological changes (porosity and PTL/catalyst interface) due to various etching conditions using X-ray tomography and correlates its influences with the electrolyzer performance.