AbstractThis study successfully synthesized a new Metal‐Organic Framework (MOF) named CJLU−L2, which was constructed from phosphorus‐containing ligands and Co(II) ions. The structure revealed through single‐crystal X‐ray diffraction (SCXRD), features a double‐walled honeycomb‐shaped structure with a one‐dimensional channel of ~6.5 Å. According to the PLATON calculation, the pore volume per unit cell of CJLU−L2 was determined to be 6825.0 Å3, constituting 57.5 % of the total crystal volume (11874.9 Å3). The Brunauer‐Emmett‐Teller (BET) surface area of CJLU−L2 was determined to be 954 m2/g by N2 adsorption measurement at 77 K. The phase purity of CJLU−L2 was verified by powder X‐ray diffraction (PXRD) and infrared spectroscopy (IR), while its thermal stability was confirmed by thermogravimetric analysis (TGA). Hydrogen adsorption experiments demonstrate that CJLU−L2 exhibits a high hydrogen adsorption capacity, indicating significant potential for gas adsorption applications.