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 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 hydrogen.