Chemical Engineering Journal, Vol.332, 608-618, 2018
Preparation of highly-hydrophobic novel N-coordinated UiO-66(Zr) with dopamine via fast mechano-chemical method for (CHO-/Cl-)-VOCs competitive adsorption in humid environment
A novel mechano-chemical strategy using dopamine to modify UiO-66(Zr) by N-coordination was proposed to enhance its competitive adsorption for acetaldehyde, chlorobenzene/H2O, both thermodynamically and kinetically. The newly synthesized material was characterized by SEM, EDX, XPS, PXRD, FT-IR, TGA/DTG and BET techniques. Results showed that N was successfully grafted into UiO-66(Zr) frameworks through coordination interaction with Zr-O clusters resulting in M-UiO-66(Zr-N-3.0). The obtained M-UiO-66(Zr-N-3.0) exhibited a significant increase in adsorption of chlorobenzene (4.94 mmol/g) and acetaldehyde (9.42 mmol/g) compared to parent UiO-66(Zr) and UiO-66(Zr)-NH2. The H2O adsorption uptake of M-UiO-66(Zr-N-3.0) decreased by 20% that of UiO-66(Zr) and 47% of UiO-66(Zr)-NH2 indicating higher hydrophobicity of the modified material. Kinetic performance indicated that diffusivity of chlorobenzene on M-UiO-66(Zr-N-3.0) was about 7.8 and 40 times higher than that of the parent UiO-66(Zr) and UiO-66(Zr)-NH2 respectively and 15.4 times higher than that of H2O on itself. Based on the results, the current N-modification strategy can be deemed as an efficient way to improve MOFs competitive adsorption towards VOCs under humid conditions and it might play active role in industries involving adsorbent applications.
Keywords:N-coordinated;Mechano-chemistry;Chlorobenzene and H2O;Competition adsorption;Thermodynamics and kinetics