Enhancing hydrogen production in alkaline electrolyzers using a surfactant with ultrafast adsorption kinetics

We compare two non-ionic surfactants as additives for alkaline water electrolysis: Surfynol 465, a surfactant with ultrafast adsorption kinetics, and the slower Triton X-100. In a laboratory cell with optical access, Surfynol 465 reduces the bubble residence time on the cathode by up to an order of magnitude, compared with Triton X-100 and the surfactant-free electrolyte. It also prevents the growth of bubbles larger than 200 μ m . Adding Surfynol 465 to 1 M KOH in an anion exchange membrane electrolyzer (AEMEL) test bench reduces the cell voltage by 140–150 mV in the initial polarization curves. The current density at 2 V nearly triples, from 0.13 to 0.37 A/cm 2 . In a week-long test, the mean cell power is about 40% higher. Downstream corrosion analyses show a strong alloy-dependent response. The surfactant reduces corrosion in stainless steel and brass, but accelerates it in carbon steel.