Adsorption of Nitrogen-Containing Compounds from Model Fuel over

Dec 15, 2015 - ABSTRACT: Adsorptive denitrogenation (ADN) was carried out by adsorption of indole (IND) and quinoline (QUI) over metal−organic ...
1 downloads 0 Views 640KB Size
Subscriber access provided by ORTA DOGU TEKNIK UNIVERSITESI KUTUPHANESI

Article

Adsorption of Nitrogen-Containing Compounds from Model Fuel over Sulfonated Metal-Organic Framework: Contribution of Hydrogen-Bonding and Acid-Base Interactions in Adsorption Imteaz Ahmed, Minman Tong, Jong Won Jun, Chongli Zhong, and Sung Hwa Jhung J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/acs.jpcc.5b10578 • Publication Date (Web): 15 Dec 2015 Downloaded from http://pubs.acs.org on December 22, 2015

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

The Journal of Physical Chemistry C is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 32

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

Adsorption of Nitrogen-Containing Compounds from Model Fuel over Sulfonated Metal-Organic Framework: Contribution of Hydrogen-Bonding and Acid-Base Interactions in Adsorption Imteaz Ahmed,a, ‡ Minman Tong,b, ‡ Jong Won Jun,a Chongli Zhong,*b Sung Hwa Jhung*a a

Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National

University, Daegu 702-701, Republic of Korea. b

State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical

Technology, Beijing 100029, China.

Abstract Adsorptive denitrogenation (ADN) was carried out by adsorption of indole (IND) and quinoline (QUI) over metal-organic frameworks (MOFs) including acidic UiO-66-SO3H for the first time. The adsorbed amount of IND increased with increasing content of –SO3H in UiO-66. The favorable effect of the –SO3H group on the adsorptive removal of IND could be explained by hydrogen bonding between the O of –SO3H and the H of IND, which was firmly supported by

ACS Paragon Plus Environment

1

The Journal of Physical Chemistry

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 32

the adsorption of pyrrole and methylpyrrole and by theoretical calculations. The application of a –SO3H group in the adsorptive removal of neutral IND is meaningful since neutral nitrogencontaining compounds are not easy to remove and since UiO-66-SO3H is reusable after simple washing with ethanol. The expected increase in QUI adsorption (due to acid-base interaction) with acidic –SO3H was observed when QUI was present at low concentrations ( 3 Å) was found between one H atom (on C of QUI) and the O atom (of –S=O) (Figure S3(b)). Curiously, the

ACS Paragon Plus Environment

11

The Journal of Physical Chemistry

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 12 of 32

calculated adsorption energies are similar each other (-212.5 and -228.5 kJ/mol for the first and second QUI, respectively), suggesting that the second QUI molecule might be adsorbed favorably if other conditions such as steric hindrance are not strict. Since the calculation results suggested that the concentration of QUI might have an influence on its adsorption behavior, we decided to carry out the adsorption of QUI at different concentrations and found an interesting result that might agree with the calculation results. Figure 6 shows the adsorption results of QUI over UiO-66 and UiO-66-SO3H(18) for different initial QUI concentrations for three adsorption times. Irrespective of adsorption time, UiO-66SO3H(18) showed higher adsorption performance for QUI than pristine UiO-66 at low initial QUI concentrations (