An efficient cathode electrocatalyst for anion exchange membrane water electrolyzer

A high performance and durable electrocatalyst for the cathodic hydrogen evolution reaction (HER) in anion exchange membrane (AEM) water electrolyzers is crucial for the emerging hydrogen economy. Herein, we synthesized Pt-C core-shell nanoparticles (core: Pt nanoparticles, shell: N-containing carbon) were uniformly coated on hierarchical MoS2/GNF using pyrolysis of h-MoS2/GNF with a Pt-aniline complex. The synthesized Pt-C core-shell@h-MoS2/GNF (with 11.3% Pt loading) showed HER activity with a lower overpotential of 30 mV at 10 mA∙cm-2 as compared to the benchmark catalyst 20% Pt-C (41 mV at 10 mA∙cm-2) with improved durability over 94 h at 10 mA∙cm-2. Furthermore, we investigated the structural stability and hydrogen adsorption energy for Pt13 cluster, C90 molecule, h-MoS2 sheet, Pt13-C90 core-shell, and Pt13-C90 core-shell deposited h-MoS2 sheets using density functional theory (DFT) simulations. We investigated the Pt-C core-shell@h-MoS2/GNF catalyst active sites during HER performance using in-situ Raman analysis as well as DFT. We fabricated anion exchange membrane (AEM) water electrolyzers with cathode catalysts of Pt-C core-shell@h-MoS2/GNF and evaluated device performance with 0.1 and 1.0 M KOH at 20 and 60°C. Our work provides a new pathway to design core-shell electrocatalysts for use in AEM water electrolyzers to generate green hydrogen.