LAUSR

MIL‐100(Fe) with good hydrothermal stability and high hydrophilicity is considered to be a potential adsorbent for adsorption heat pumps (AHPs). However, its water vapor adsorption performance at low relative humidity needs to be improved. In this study, composite adsorbent LiCl@MIL‐100(Fe) was synthesized by impregnating LiCl aqueous solution in MIL‐100(Fe). The effects of the LiCl loading in the composite on the crystal structure, morphology, composition, pore structure as well as the vapor adsorption/desorption performance of the composites were carefully studied. The results showed that on the premise of ensuring no leakage, the LiCl loading in the composite was up to 32.9 wt%. At 20% relative humidity (RH), the saturated adsorption ratio of the composite (0.260 g/g) was higher than that of original MIL‐100(Fe) (0.054 g/g). Meanwhile, the water adsorption rate of the new composite adsorbent was faster than pristine MIL‐100(Fe). Moreover, after 50 cycles of vapor adsorption/desorption, the composite adsorbent showed a satisfactory stability. All these indicate that the new LiCl@MIL‐100(Fe) composite adsorbent will be a prospective candidate for high‐efficiency AHPs.