MIL-100(Fe) as a functional sorbent coating: Green synthesis, energetic insights, and heat exchange efficiency

Efficient air dehumidification is essential for improving indoor air quality and energy efficiency in cooling applications. This study explores the use of MIL-100(Fe) as a high-performance desiccant coating for fin-tube heat exchangers in air dehumidification systems. MIL-100(Fe) was synthesized using an environmentally friendly method and comprehensively characterized by X-ray diffraction (XRD), nitrogen adsorption, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) to confirm its crystal structure, morphology, high porosity, and thermal stability. The water vapor adsorption and desorption isotherms were analyzed at different temperatures and fitted using the Dubinin-Astakhov (D-A), Sun-Chakraborty (S-C), and universal isotherm models. The results revealed insights into the stepwise adsorption mechanism and thermodynamics, correlating with the material’s crystal structure. To enhance coating stability, four different binders (hydroxyethyl cellulose, sodium polyacrylate, cellulose acetate, and polyvinyl alcohol) were evaluated. The optimized 10% hydroxyethyl cellulose binder provided a balance between mechanical stability and adsorption capacity. The coated heat exchanger was tested under actual operating conditions, demonstrating twice the moisture removal efficiency of a conventional silica gel-coated heat exchanger. The integration of site-resolved thermodynamic modeling with experimental validation under realistic operating conditions offers new insights into MOF-based thermal management materials and highlights MIL-100(Fe)’s potential for energy-efficient dehumidification systems.