Synergistic Pt/Co(OH)2/PTI enhances H2O dissociation and H* adsorption for efficient alkaline hydrogen evolution

Anion-exchange membrane water electrolyzers (AEMWE) are promising for clean hydrogen production. However, the high energy barriers associated with water adsorption and dissociation combined with the high adsorption energy of hydrogen intermediates (H*) in alkaline environment result in slow kinetics for the hydrogen evolution reaction (HER). To tackle this, we report a catalyst comprising Pt nanoparticles loaded on Co(OH) 2 /PTI nanosheets (Pt/Co(OH) 2 /PTI) for efficient alkaline HER at high current densities. Operando characterization indicates that Co(OH) 2 promotes H 2 O adsorption and dissociation, while the Pt nanoparticles optimize H* adsorption energy, enabling preferential H* adsorption at the Pt site to facilitate H 2 generation and desorption. Furthermore, the ultra-thin poly (triazine imide) (PTI) support prevents the Pt nanoparticles aggregation, thereby enhancing catalyst stability. As a result, the synergistic Pt/Co(OH) 2 /PTI achieves superior HER performance, demanding an overpotential of merely 7 mV to achieve a current density of 10 mA cm −2 and just 220 mV to drive 1 A cm −2 , and it maintains stable for over 220 h under the condition of 1 A cm −2 . Additionally, the electrolyzer assembled using Pt/Co(OH) 2 /PTI as the cathode demonstrates stable operation for 200 h at 0.5 A cm −2 under 70 °C, highlighting its strong potential for industrial applications.