Oxygen evolution catalysts under proton exchange membrane conditions in a conventional three electrode cell vs. electrolyser device: a comparison study and a 3D-printed electrolyser for academic labs

Developing active and stable oxygen evolution reaction (OER) catalysts that can operate in electrolyser environments is of utmost important in order to produce H₂ gas for electricity generation. Currently in academia, many of these studies are carried out in conventional three-electrode cell set-ups; however, this configuration may not accurately represent conditions experienced under practical electrolyser conditions. Herein, a range of transition metal oxide (TMO) catalysts are evaluated and compared in a three-electrode cell and in an electrolyser. We show that the same catalyst significantly underperforms in a three-electrode cell. Hence, many OER catalysts in academic labs may have been erroneously omitted from further optimisation processes due to showing ‘poor’ performance in conventional three-electrode cells. Herein, we wish to show this discrepancy experimentally and suggest a solution to scientists wanting to find active OER catalysts by using 3D-printing to inexpensively manufacture electrolyser devices for OER catalyst evaluation.