Dry gel conversion synthesis and performance of glass-fiber MIL-100(Fe) composite desiccant material for dehumidification

Metal organic frameworks (MOFs) MIL-100(Fe) is considered to be a promising porous adsorbent for dehumidification due to its good hydrophilicity and hydrothermal stability. However, the powdery MIL-100(Fe) prepared by the conventional hydrothermal method is not suitable for industrial rotary desiccant dehumidifier. In order to produce a high-performance rotor core component, a new dry gel conversion in situ synthesis strategy for glass-fiber MIL-100(Fe) monolithic adsorbent was proposed in this paper. The effects of the reaction sol concentration on the crystalline phase, morphology, pore structure , adsorption/desorption performance and the cycling stability of the monolith were discussed in detail. The results showed that MIL-100(Fe) crystals which evenly dispersed in the surface and voids of glass fiber, could be conveniently synthesized in the reaction sols with molar ratios of 1Fe (III)/0.67BTC/xH 2 O (x = 93–185). Among them, the MIL-100(Fe) monolith obtained at x = 93 exhibited a high loading (85.7%), large BET specific surface area (1441 m 2 /g), S-shaped water vapor adsorption isotherm and high saturated adsorption ratio (0.496 g/g) at 298 K and 60% RH , low desorption activation energy (48.28 kJ/mol) as well as a reliable cycling stability. Favorable adsorption/desorption performance of MIL-100(Fe) monolith and convenient dry gel preparation process provide a guidance for the manufacture of high-performance dehumidification rotary wheel.