One‐Step Modulated Hydrothermal Synthesis of Nickel‐Doped HKUST‐1 for Improved Hydrogen Storage Performance

Metal‐organic frameworks (MOFs) have shown exceptional capability of hydrogen storage due to the porous attributes and open metal sites (OMSs) for physical bonding, leading to attempts of hydrogen (H 2 ) sorption for clean energy purposes. However, it has been a great challenge to balance between developing a simple MOF synthesis method for industrialization and pursuing high H 2 uptake capacities for hydrogen storage applications. Herein, we report a one‐step modulated hydrothermal (MHT) method for doping nickel ions (Ni 2+ ) into [Cu 3 (BTC) 2 (H 2 O) 3 ] n (where BTC is benzene‐1,3,5‐tricarboxylate), or HKUST‐1. Such a Ni@HKUST‐1 MOF possesses a higher surface area (1536 m 2 g −1 vs. 1213 m 2 g −1 ) with fine‐tuned structure, which enables a H 2 uptake capacity of 4.5 wt%, or 39.8 g L −1 , at 77 K and 100 bar. This result is 25% greater than that of pristine HKUST‐1, which is 3.6 wt%. Molecular simulations demonstrate the advantages of introducing Ni 2+ to the parent MOF, including possessing stronger adsorption of H 2 and fine‐tuning the microstructure to allow more space for combination with OMSs. Therefore, this work gives a prospective solution to the challenge of industrially synthesizing MOF for practical hydrogen storage and paves the way for techno‐economically efficient application of MOF in multiple fields.