CO2 Capture and Positional Disorder in Bis(135-benzenetricarboxylate) Tri-copper Hydrate: An In Situ Laboratory X-ray Powder Diffraction Study

Published

November 11, 2015

Author(s)

Winnie K. Wong-Ng, Igor Levin, James A. Kaduk, Laura Espinal, Hui Wu

Abstract

Ambient-temperature capture of CO2 by metal-organic framework Cu3(BTC)2 (BTC ≡ 1,3,5-benzenecarboxylate), known as HKUST-1, have been studied in situ in a laboratory X-ray powder diffractometer under gas-flowing conditions. The diffraction patterns were collected at partial pressures of CO2 (p(CO2)) ranging from 0.2 bar to 6 bar. Rietveld refinements combined with the difference Fourier maps identified two principal absorption sites, which agreed with the results of previous low-temperature neutron diffraction studies. At ambient temperature, the CO2 molecules on both sites exhibit considerable positional and rotational disorder, which contrasts with their ordered positions determined by neutron diffraction at cryogenic temperatures. The amount of the absorbed CO2 increased continuously with increasing p(CO2) and reached about1.8 CO2 molecules per Cu atom at p(CO2)=6 bar. The results of this work, while providing new insights into the CO2 absorption of HKUST-1, demonstrate that laboratory X-ray powder diffraction can be successfully used to identify locations of CO2 molecules during in situ gas-absorption experiments.

Citation

Powder Diffraction

Volume

656

Pub Type

Journals

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DOI Link

Keywords

Metal Organic Framework (MOF), Cu-BTC, laboratory X-ray powder diffraction, structure as a function of pCO2, location of CO2 groups

Citation

Wong-Ng, W. , Levin, I. , Kaduk, J. , Espinal, L. and Wu, H. (2015), CO2 Capture and Positional Disorder in Bis(135-benzenetricarboxylate) Tri-copper Hydrate: An In Situ Laboratory X-ray Powder Diffraction Study, Powder Diffraction, [online], https://doi.org/10.1016/j.jallcom.2015.09.078 (Accessed February 6, 2025)