Phytic acid-encapsulated MIL-101(Cr): Remarkable adsorbent for the removal of both neutral indole and basic quinoline from model liquid fuel

다국어 초록 (Multilingual Abstract)

<P><B>Abstract</B></P> <P>Phytic acid (PA) encapsulated metal-organic framework (MIL-101(Cr) or Cr-benzenedicarboxylate) was prepared for the first time; and applied in the adsorptive removal of nitrogen-containing compounds (NCCs) from liquid model fuel. The modified MIL-101(Cr)s resulted in very promising maximum adsorption capacities (<I>Q</I> <SUB>0</SUB>) for both the neutral indole (IND, <I>Q</I> <SUB>0</SUB> = 543 mg/g) and basic quinoline (QUI, <I>Q</I> <SUB>0</SUB> = 549 mg/g) compared to the pristine MIL-101(Cr) (IND; <I>Q</I> <SUB>0</SUB> = 416 mg/g; QUI, <I>Q</I> <SUB>0</SUB> = 409 mg/g). Or, the <I>Q</I> <SUB>o</SUB> values of PA(3)@MIL-101(Cr) for the adsorptions of IND and QUI stand at the second and fifth positions, respectively, among any previously reported results. Moreover, the new adsorbent showed around 8 times adsorption capacity to that of conventional activated carbon. PA encapsulation onto MIL-101(Cr) resulted in 86% and 91% increased adsorption (based on unit surface area of adsorbent) of IND and QUI, respectively. Moreover, PA(3)@MIL-101(Cr) showed more effective/selective adsorption than pristine MIL-101(Cr) towards the NCCs especially when toluene (as aromatics) was added as co-solvent. The extraordinary adsorptions could be described by the hydrogen bonding and the acid-base interactions between the NCCs and the PA functionalities of the adsorbents. Moreover, the PA@MIL-101(Cr)s could be regenerated via a simple manner and reused in adsorptions up to several cycles. Therefore, the novel PA@MOF materials could be suggested as a type of very efficient adsorbents for the adsorptive removal of both neutral and basic NCCs from liquid model fuel.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Phytic acid (PA) was loaded onto a MOF to get novel adsorbent for fuel purification. </LI> <LI> PA@MOF had ~8 times adsorption for indole and quinoline to that of activated carbon. </LI> <LI> PA@MOF showed more effective adsorption than MOF when aromatics co-present. </LI> <LI> More effective adsorption could be explained via H-bonding and acid-base interaction. </LI> <LI> PA@MOF could be regenerated via solvent washing and reused up to several cycles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>