Enhancing hydrogen production in alkaline electrolyzers by using an ultra-fast kinetics surfactant

Abstract

We study the effect of surfactant adsorption kinetics on water electrolysis performance using Surfynol 465, an ultrafast-kinetics surfactant. High-speed optical diagnostics reveal that Surfynol 465 reduces bubble residence time by an order of magnitude. Compared to the slower surfactant Triton X-100 and the surfactant-free baseline, it also prevents the growth of large bubbles ($>200\ \mu$m). We validated these results on an anion-exchange membrane electrolyzer (AEMEL) test bench. Adding Surfynol 465 to the $1\text{ M KOH}$ electrolyte decreases cell overpotential by 140--150 mV. It nearly triples the current density (from 0.13 to 0.37 A/cm$^2$ at 2 V) and increases average power by 40\% during a week-long test. Furthermore, downstream corrosion analyses reveal a strong alloy-dependent response. The surfactant reduces degradation in stainless steel and brass but accelerates corrosion in carbon steel.