Interactions of NO₂ with Zr-Based MOF: Effects of the Size of Organic Linkers on NO₂ Adsorption at Ambient Conditions

Abstract

Zirconium-based metal organic framework (Zr-MOF), UiO-66 and UiO-67, were synthesized and used as adsorbents of NO(2) at ambient temperatures in either dry or moist conditions. The samples were characterized before and after exposure to NO(2) by X-ray diffraction, scanning electron microscopy, N(2)-adsorption at 77 K, thermal analysis, and infrared spectroscopy. The results indicate the important effect of a ligand size on the adsorption of NO(2) on Zr-MOF materials. While the large size of the 4,4-benzenebiphenyldicarboxylic acid (BDPC) ligand has a positive impact on the adsorption of NO(2) on UiO-67 in moist conditions, the opposite effect is found in dry conditions. The large pore volume of UiO-67 enhances the adsorption of moisture and formation of nitric and nitrous acids. The small pore sizes of UiO-66 favor the NO(2) removal in dry conditions via dispersive forces. Upon interaction of NO(2) molecules with the Zr-MOF in dry conditions, the bond between the organic linker and metallic oxide center is broken, leading to the formation of nitrate and nitrite species. Moreover, organic ligands also contribute to the NO(2) reactive adsorption via nitration reaction.

Selective decontamination of the reactive air pollutant nitrous acid via node-linker cooperativity in a metal–organic framework

“…[35][36][37][38][39][40] Beyond these applications, specic MOFs have been featured in environmental decontamination strategies. [41][42][43][44][45][46][47][48] The present work illustrates a chemisorption solution ( Fig. 1) for nitrous acid (and ultimately NO x ) where capacity, reactivity, and selectivity are greater than under physisorption conditions.…”

Extraordinary NO2 Removal by the Metal–Organic Framework UiO‐66‐NH2

“…The authors did not discuss the generation of nitric oxide (NO), a common byproduct from the oxidation of surfaces by NO 2 . Bandosz and co‐workers investigated UiO‐66 and the linker‐extended version UiO‐67 impregnated with urea and melamine . In general, NO 2 capacity was found to increase with increasing linker size and the addition of urea.…”

Insights into the separation performance of MOFs by high-performance liquid chromatography and in-depth modelling

“…7A); -K L = 99 L mol -1 and C* MOFmax = 0.14 mol L -1 for BZD (Fig. 7B); 21 -K L = 652 L mol -1 and C* MOFmax = 0.14 mol L -1 for DCP (Fig. 7C).…”

“…One UiO-67 unit cell is occupied by four octahedral pores and eight tetrahedral pores. UiO-67 has been successfully applied in gas adsorption [21] and catalysis [22]. Recently, several studies have reported the successful use of UiO-66 as stationary phases in HPLC [23][24][25].…”