Comparative analysis of HER and OER electrocatalysts for industrial water splitting: Bridging laboratory overpotentials and electrolyzer performance
Year: 2026
Type: conference-paper
Abstract: In a working electrolyser, the quantity of green hydrogen produced is governed by catalyst behaviour under operating load rather than by the figures of merit measured in three electrode cells. This work focuses on the overpotential at 10 mA cm -2 , the metric most frequently used to rank hydrogen and oxygen evolution reaction (HER and OER) catalysts, and argues that it is a poor indicator of industrial viability. Device level data for acidic and alkaline cells confirm this. Catalysts that fall within a narrow window of low current overpotential can differ by more than an order of magnitude in durability once they are operated at the ampere per square centimetre current densities of practical stacks. To explain the gap between laboratory and device performance, four aspects are examined in turn: the definition of overpotential, the limitations of a single activity point, stability at high current density, and the way precious metal loading enters the levelized cost of hydrogen. On this basis, a concise evaluation framework of four reportable quantities is proposed: full cell voltage at an industrial current density, durability and voltage decay rate at that current density, loading of critical elements, and the catalyst contribution to hydrogen cost. The objective is to render cross study comparison meaningful and to align catalyst screening with the conditions under which electrolysers actually operate.
Source: E3S Web of Conferences
Institutions: Université Ibn-Tofail, Université Mohammed VI Polytechnique
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7225237686