Large Adsorption Capacity for Space Molecular Pollutants Realized by a Metal-Organic Framework

The rapid development of capable spacecraft coatings for removing volatile organic compounds (VOCs) demands materials with a large adsorption capacity to ensure a long-duration exploration mission in a low Earth orbit (LEO). MIL-53(Al) with abundant sites exhibits resistance to the space environment in the LEO and shows great potential for VOC removal. This study combined an adsorption experiment and first-principles simulations to investigate the adsorption performance of MIL-53(Al). MIL-53(Al) demonstrated an excellent adsorption capacity for various VOCs, reaching 606.04 mg/g for m-xylene and 22.69 cm³/g for methane, which is 6 times higher than traditional adsorption methods. First-principles simulations revealed that the adsorption capacity is significantly influenced by micropores through the pore effect and breath effect, which restrict diffusion and enhance adsorption, respectively. Additionally, we predicted the adsorption properties of VOCs that are difficult to characterize through ground-based simulated experiments, further validating the potential application of MIL-53(Al) for VOC removal in the LEO. This work expands the application range of MIL-53(Al), optimizes VOC removal strategies, and offers a novel approach to protecting spacecraft in the LEO. Our findings contribute to the development of advanced materials for space exploration and provide valuable insights into the design of efficient VOC removal systems for spacecraft in the LEO.