Design development of bimetallic clusters onto copper-benzimidazole metal–organic frameworks and their derived materials as electrocatalysts for water electrolysis and hydrogen fuel cell applications

Abstract

The development of efficient and cost-effective electrocatalysts is essential for advancing clean hydrogen energy technologies. In this study, a copper-based zeolitic imidazolate framework (CuZIF) was synthesized and further modified with platinum (Pt) and ruthenium (Ru) via electroless plating to obtain PtRu@CuZIF, followed by pyrolysis to form PtRu@Cu–N/C. Comprehensive characterization was confirmed using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction spectroscopy (XRD), Brunauer–Emmett–Teller (BET) analysis, and scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) analysis. Electrochemical evaluations in 0.1 M KOH demonstrated that the PtRu@CuZIF electrocatalyst achieved superior hydrogen evolution reaction (HER) performance, with a low overpotential of 284 mV at 10 mA cm–2, a Tafel slope of 119 mV dec–1, and a high turnover frequency of 7.08 × 10–4 s–1, following a Volmer–Heyrovsky mechanism. Although CuZIF showed the highest conductivity and electrochemical surface area, its HER performance was hindered by dispersion of PtRu particles. The PtRu@Cu–N/C electrocatalyst showed the highest stability and power output, achieving an energy density of 165.78 Wh kg–1 and a power density of 497.33 W kg–1. These findings highlight the potential of bimetallic MOF-derived materials for integrated water electrolysis and hydrogen fuel cell applications.