Synthesis and hydrogen storage properties of zirconium metal-organic frameworks UIO-66(H2ADC) with 9,10-anthracenedicarboxylic acid as ligand

Zirconium metal-organic frameworks UIO-66(H2ADC) was synthesized with 9,10-anthracenedicarboxylic acid as ligand by the simple solution method (SS)and solvothermal reaction (S). The influence of different reaction conditions on the structure and properties of UIO-66(H2ADC) were investigated. The structures of samples UIO-66(H2ADC) were characterized by the powder X-ray diffraction, infrared spectroscopy and nitrogen sorption technique. UIO-66(H2ADC) and UIO-66 had the same face-centered cubic topology. When the feed ratio was 1.2:1 (metal:organic linker), the reaction temperature was 45 °C and reaction time was 12 h by the simple solution method (which was named UIO-66(H2ADC)-SS), UIO-66(H2ADC)-SS had the best crystallinity and BET specific surface area (432 m2/g) with average pore size of around 4.38 nm. And when at reaction condition was temperature of 85 °C, the feed ratio of 0.61:1(metal:organic linker) and time of 24 h by solvothermal reaction (denoted as UIO-66(H2ADC)-S), UIO-66(H2ADC)-S had the biggest BET specific surface area (772 m2/g) and had smaller average size of around 2.73 nm. The hydrogen storage properties of different samples were determined by hydrogen storage analyzer. UIO-66(H2ADC)-S and UIO-66(H2ADC)-SS hydrogen uptake capacity were 29.2 and 10.9 mg/g at 298 K, 5 MPa, respectively. When considering of unit the specific surface area adsorption UIO-66(H2ADC)-S and UIO-66(H2ADC)-SS were 0.0378 and 0.0252 mg/m2, but UIO-66 was 0.0233 mg/m2 ,which shown UIO-66(H2ADC) have good hydrogen uptake capacity. Interaction energy of UIO-66(H2ADC) and hydrogen was − 5.73 kJ/mol.