Efficient H2 adsorption using a bimetallic Ni–Zn zeolite imidazole skeleton

Hydrogen is regarded as one of the most promising energy sources of the future, due to its low-cost, zero-pollution, and high-heat value. Nevertheless, traditional methods of storing hydrogen are commonly accompanied by the risk of leaks and explosions, so how to store and transport hydrogen safely and efficiently is a critical issue that needs to be addressed. Solid-state hydrogen storage is the most attractive way to store hydrogen in nanomaterials by chemical or physical adsorption, which has the advantages of high energy density and good safety. Here, a rational Ni–Zn bimetallic MOF has been constructed by a straightforward synthetic technique, in which the Zn atom was partially replaced by the Ni atom. The micropore rate of the Ni–Zn bimetallic MOFs is higher than that of ZIF-8. In addition, the presence of Ni provides more unsaturated metal sites and strengthens the bonding between hydrogen molecules and Ni, effectively improving the hydrogen storage capacity of Ni–Zn bimetallic MOFs. The experimental results show that the hydrogen adsorption capacity of Ni–Zn bimetallic MOFs can reach 1.35 wt% at 77 K and 1 bar.