Title: Insights into Supramolecular Sites Responsible for Complete Separation of Biomass-Derived Phenolics and Glucose in Metal–Organic Framework NU-1000

Abstract

The molecular origins of adsorption of lignin-derived phenolics to metal–organic framework NU-1000 are investigated from aqueous solution as well as in competitive mode with glucose present in the same aqueous mixture. A comparison of adsorption equilibrium constants ($$K_{ads}$$) for phenolics functionalized with either carboxylic acid or aldehyde substituents demonstrated only a slight increase (less than a factor of 6) for the former according to both experiments and calculations. This small difference in $$K_{ads}$$ between aldehyde and carboxylic-acid substituted adsorbates is consistent with the pyrene unit of NU-1000 as the adsorption site, rather than the zirconia nodes, while at saturation coverage, the adsorption capacity suggests multiple guests per pyrene. Experimental standard free energies of adsorption directly correlated with the molecular size and electronic structure calculations confirmed this direct relationship, with the pyrene units as adsorption site. The underlying origins of this relationship are grounded in noncovalent $π–π$ interactions as being responsible for adsorption, the same interactions present in the condensed phase of the phenolics, which to a large extent govern their heat of vaporization. Thus, NU-1000 acts as a preformed aromatic cavity for driving aromatic guest adsorption from aqueous solution and does so specifically without causing detectable glucose adsorption from aqueous solution, thereby achieving complete glucose–phenolics separations. The reusability of NU-1000 during an adsorption/desorption cycle was good, even with some of the phenolic compounds with greatest affinity not easiliy removed with water and ethanol washes at room temperature. A competitive adsorption experiment gave an upper bound for $$K_{ads}$$ for glucose of at most 0.18 M^–1, which can be compared with $$K_{ads}$$ for the phenolics investigated here, which fell in the range of 443–42 639 M^–1. The actual value of $$K_{ads}$$ for glucose may be much closer to zero given the lack of observed glucose uptake with NU-1000 as adsorbent.

Authors:

Yabushita, Mizuho ^[1]; Li, Peng  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-4273-4577"

Durkin, Kathleen A. ^[3]; Kobayashi, Hirokazu ^[4]; Fukuoka, Atsushi  ^[4];

• Search DOE PAGES for author "Fukuoka, Atsushi"
• Search DOE PAGES for ORCID "0000-0002-8468-7721"

Farha, Omar K.  ^[5];

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• Search DOE PAGES for ORCID "0000-0002-9904-9845"

Katz, Alexander  ^[6]

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• Search DOE PAGES for ORCID "0000-0003-3487-7049"

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+ Show Author Affiliations

1. Hokkaido Univ., Sapporo (Japan). Inst. for Catalysis; Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engineering
2. Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry
3. Univ. of California, Berkeley, CA (United States). College of Chemistry
4. Hokkaido Univ., Sapporo (Japan). Inst. for Catalysis
5. Northwestern Univ., Evanston, IL (United States). Dept. of Chemistry; King Abdulaziz Univ., Jeddah (Saudi Arabia). Dept. of Chemistry
6. Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engineering

Publication Date:

Wed Mar 15 00:00:00 EDT 2017

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Energy Frontier Research Center for Inorganometallic Catalyst Design (ICDC)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1469883

Grant/Contract Number:  

SC0012702

Resource Type:

Accepted Manuscript

Journal Name:

Langmuir

Additional Journal Information:

Journal Volume: 33; Journal Issue: 17; Related Information: ICDC partners with University of Minnesota(lead); Argonne National Laboratory; Clemson University; Dow Chemical Company; Northwestern University; Pacific Northwest National Laboratory; University of California Davis; University of Washington; Journal ID: ISSN 0743-7463

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 09 BIOMASS FUELS; catalysis (heterogeneous), materials and chemistry by design, synthesis (novel materials)