As an important chemical raw material, formic acid is widely used in many fields. In many industrial processes, a large amount of low-concentration formic acid solution is produced and cannot be used directly. If it is discharged into the environment, it will lead to a serious waste of resources and environmental pollution. Therefore, it is of great practical significance to concentrate and reuse formic acid aqueous solutions. This paper reviews the current methods for the concentration of formic acid aqueous solutions, including distillation, extraction, membrane distillation, electrodialysis, dehydrating agent concentration and freeze concentration. The underlying principles and application examples of various concentration methods are introduced, and their advantages and disadvantages are summarized. Finally, possible further advances in technology for the concentration of formic acid aqueous solutions are discussed.

Metal-organic frameworks (MOFs) have emerged as exceptional materials for atmospheric water harvesting (AWH) due to their superior adsorption properties in low humidity conditions (≤ 20% RH), but most MOF adsorbents typically exist in powder form, thus their aggregation induces significant transfer resistance to limit their adsorption kinetics and practical application potential. Here we prepared an organic-inorganic MOF-303@poly(acrylates) composite by in-situ growing MOF-303 within porous poly(acrylates) spheres. Our results demonstrate that the 87% loading of MOF-303@poly(acrylates) exhibits uniformly dispersed crystals with a crystal size that is 40% smaller compared to pure MOF-303 powder, while maintaining a water vapor adsorption capacity of 0.348 g·g⁻¹ at 20% RH and 298 K, which is comparable to that of an equivalent mass of the pure MOF-303 powder. In the dynamic water vapor test with a constant flow rate (50 mL·min⁻¹), the adsorption and desorption rates of the composite are 2.74 and 2 times faster than those of MOF-303 powder. After 100 consecutive adsorption and desorption cycles at 1780 mL·min⁻¹ (0.95 m·s⁻¹, light air), the water vapor adsorption capacity showed no significant decline. This composite strategy not only enhances adsorption kinetics but also advances MOF-based AWH systems for engineering applications.