Bimetallic MIL-88B(Fe2/Ni)-NH2/rGO hybrid as an efficient Low-Pt support for enhanced ethanol electro-oxidation and its application in direct ethanol fuel cell

Developing efficient and low-Pt electrocatalysts is critical for the commercialization of direct ethanol fuel cells (DEFC). Herein, a novel bimetallic iron-nickel metal-organic framework, MIL-88B(Fe2/Ni)-NH2 ((Fe2/Ni)MOF), was synthesized using 2-aminoterephthalic acid as a linking ligand. Different loadings of reduced graphene oxide (rGO, 1–8wt%) were incorporated via solvothermal synthesis to enhance structural stability and conductivity, forming 1–8wt% rGO-(Fe2/Ni)MOF composites. These hybrids serve as supports for Pt catalysts, producing Pt/[1–8wt% rGO-(Fe2/Ni)MOF] electrocatalysts. The synthesized materials were characterized using FT-IR, XRD, SEM, TEM, EDS mapping, XPS, cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, and direct ethanol fuel cell performance testing. Among the prepared catalysts, Pt/[5 wt% rGO-(Fe2/Ni)MOF] exhibited the highest electrocatalytic activity toward ethanol oxidation, achieving a current density of 50.37 mA cm−2 at 0.86 V. In DEFC testing at 60 °C with 3M ethanol, this catalyst delivered a power density three times higher than the Pt/CC as control catalyst, with an open-circuit voltage of 0.54 V compared to 0.35 V for Pt/CC. These results demonstrate that the designed rGO-MOF hybrid is an efficient and durable Pt support, offering significant potential for DEFC applications and sustainable energy conversion.