Effect of Textural Properties on the Adsorption and Desorption of Toluene on the Metal-Organic Frameworks HKUST-1 and MIL-101

Abstract

ABSTRACT:The adsorption and desorption of toluene on metal-organic frameworks HKUST-1 and MIL-101 were studied. The adsorption isotherms and kinetic curves of toluene on HKUST-1 and MIL-101 were separately measured by gravimetric method. Temperature-programmed desorption experiments were carried out for estimating the interaction of toluene with the surfaces of HKUST-1 and MIL-101. Our experimental results showed that the isotherms of toluene on the adsorbents were well fitted by the Langmuir-Freundlich equation. The maximum amount of toluene adsorbed on MIL-101 was 15.1 mmol/g, which was much higher than that adsorbed on HKUST-1 (6.6 mmol/g). The high adsorption capacity of MIL-101 can be attributed to its higher surface area. However, the isotherm of toluene at P/P 0 < 0.09 on HKUST-1 was much higher than that on MIL-101 owing to the smaller pore size of HKUST-1. It is suggested that HKUST-1 had better adsorption performance than MIL-101 at low concentration of volatile organic compounds. The desorption activation energies, E d , of toluene on HKUST-1 and MIL-101 were 43.8 and 30.2 kJ/mol, respectively, meaning that the interaction of toluene with HKUST-1 was stronger than that with MIL-101. In addition, the diffusion coefficient of toluene within HKUST-1 was smaller than that within MIL-101. Results of thermal desorption experiments showed that the desorption efficiency of toluene from HKUST-1 and MIL-101 can separately reach above 93% and nearly 100% at 393 K, respectively.

An electrochemical immunosensor coupling a bamboo-like carbon nanostructure substrate with toluidine blue-functionalized Cu(ii)-MOFs as signal probes for a C-reactive protein assay

“…Under stirring at room temperature, a Soxhlet extractor was used to add solution B dropwise to solution A. Aer dropwise addition and continuous stirring for 1 h at room temperature, centrifugation was carried out followed by washing with water and ethanol three times, respectively. Finally, Cu(II)-HKUST-1 nanoparticles were obtained aer being centrifuged and vacuum dried at 40 C for 48 h. 33 Synthesis of Au NPs/Cu(II)-HKUST-1 50 mg of the Cu(II)-HKUST-1 solid powder and 10 mL of DI water were added into a 250 mL three-neck ask followed by uniformly dispersing with ultrasound. Then, 20 mL of the Au nanosol was added dropwise into the ask using a Soxhlet extractor and stirring at normal temperature for 24 h to fully absorb the Au nanoparticles.…”

Hierarchical Metal–Organic Frameworks with Macroporosity: Synthesis, Achievements, and Challenges

“…TEM further confirmed the abundance of mesopores and macropores (pore sizes of 40–100 nm) in the final product. Because of the presence of macropores which contribute to high molecular diffusion, the hierarchical MOF exhibited a high toluene storage capacity (646 mg g −1 at 298 K), representing a 25 wt% increase compared to that for the non-hierarchical HKUST-1 (516 mg g −1 ) [ 80 ]. This value is also much higher than other microporous MOFs and zeolites [ 81 – 83 ].…”

Adsorption and Detection of Hazardous Trace Gases by Metal–Organic Frameworks

“…A comparison of the toluene adsorption isotherms of two MOFs, HKUST‐1 and MIL‐101, is given by Xu et al MIL‐101 has two types of mesoporous cages, 34 and 29 Å in diameter with 12 and 16 Å × 14.5 Å windows . The pore system of HKUST‐1 shows a window size of 9 Å and a cage size of 10.8 Å.…”