CO2 Adsorption on MIL-53(Al) Crystals Formed on Anodized Aluminum Oxide Disc

Anjola Uprety, Cynthia Pyles, and Aaron Massari

Department of Chemistry, University of Minnesota

Abstract

The microporous structure of MIL-53(Al) allows for unique

properties such as gas adsorption and separation. MIL-53(Al)

demonstrates selectivity for CO2, making it an attractive

macromolecular structure to study for CO2 adsorption

purposes. Anodized Aluminum Oxide (AAO) membranes

were reacted with 1,4-benzenedicarboxylic acid at 85oC.

Crystals were successfully synthesized on the AAO

membranes, as characterized via SEM, BET N2 adsorption

isotherms, and FTIR as a function of time reacted. Samples

were soxhletted in N,N-dimethylformamide (DMF) for 12

hours before activating for 18 hours at 500K. MIL-53 crystals

grown on AAO substrates have not been previously utilized

for their CO2 adsorptive properties, successfully adsorbed

approximately. By FTIR, we observed approximately 300

mOD of CO2 after exposure to gaseous CO2 at a pressure of 5

psi for four hours. The 2337 cm-1 FTIR peak associated with

monomeric CO2 adsorbed on MIL-53 is consistent with the

literature, as is the broad shoulder at 2334 cm-1, indicative of

dimeric CO2.

Synthesis

Anodized Aluminium

Oxide

+ 1,4-benzenedicarboxylic

acid

Water MIL-53

+Water

Zhang, Y.L. et al. Constructing Free Standing Metal Organic Framework MIL-53 Membrane

Based on Anodized Aluminum Oxide Precursor. Sci. Rep. 4, 4947; DOI:10.1038/srep04947

(2014).

0.144g

SEM Images a b

d e f

c

Figure 1: SEM images of AAO membranes reacted different amounts of time with

1,4-benzenedicarboxylic acid at 85oC. a) AAO disc before the reaction at t = 0h, b) t

= 6h, c) t = 18h, d) t = 24h, e) t = 30h, f) t = 48h

Acknowledgement

Conclusion and Future Work

• Anodisc samples scattered less compared to KBr

pellet samples

• Effectively activated anodisc samples and loaded

with CO2

• Observed crystals growth on Anodized Aluminum

Oxide substrate

• Further optimize reaction conditions to

synthesize more homogenous samples

• Better understand anomalous isotherm

behavior of MIL-53 samples

• Study the dynamics of CO2 adsorbed on MIL-

53 in addition to other microporous structures

such as ZIF-8 and MOF-74 (Mg) using 2D-IR

FTIR Spectra

10g

(i) (ii)

(iii)

Figure 2:

i) FTIR spectra of AAO disc

before reaction and after 48

reacting for 48 hours

ii) FTIR spectra of AAO disc vs

AAO Disc containing MIL-53

crystals when loaded with CO2.

iii) The portion of spectra (ii)

zoomed in, showing bound

monomeric and dimeric CO2.

BET Isotherm

Figure 3: I ) BET N2 isotherm of MIL-53 crystals

grown on anodized aluminum oxide membrane, II)

micropore size distribution

Future Work

I.

II.

Heat+Pressure