Selective capture of carbon dioxide from hydrocarbons using a metal-organic framework

Efficient and sustainable methods for carbon dioxide (CO2) capture are highly sought after. Mature technologies involve chemical reactions that absorb CO2, but they have many drawbacks. Energy-efficient alternatives may be realized by porous physisorbents with void spaces that are complementary in size and electrostatic potential to molecular CO2. Here, we present a robust, recyclable and inexpensive adsorbent termed MUF-16 (MUF = Massey University Framework). This metal-organic framework captures CO2 with a high affinity in its one-dimensional channels. The position of the CO2 molecules sequestered in the framework pores, as determined by X-ray crystallography, illustrate how complementary noncovalent interactions envelop the CO2 while repelling other guest molecules. The low affinity of the MUF-16 pores for these competing gases underpins new benchmarks for the adsorption of CO2 over methane, acetylene, ethylene, ethane, propylene and propane. IAST calculations show that for 50/50 mixtures at 293 K and 1 bar, the CO2/CH4 selectivity is 6690 and the CO2/C2H2 selectivity is 510, for example. Breakthrough gas separations under dynamic conditions benefit from short time lags in the elution of the weakly-adsorbed component to deliver high-purity hydrocarbon products. Ultimately, MUF-16 may be applicable to the removal of CO2 from sources such as natural gas and chemical feedstocks.

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Selective Capture of Carbon Dioxide from Hydrocarbons Using a Metal-Organic Framework: Relevance to the Purification of Natural Gas and Acetylene

10.26434/chemrxiv.9729665 ◽

2020 ◽

Cited By ~ 1

Author(s):

Omid Taheri Qazvini ◽

Shane G. Telfer

Keyword(s):

Carbon Dioxide ◽

Natural Gas ◽

Noncovalent Interactions ◽

Metal Organic Framework ◽

Time Lags ◽

Guest Molecules ◽

X Ray Crystallography ◽

Metal Organic ◽

Short Time ◽

Organic Framework

Efficient and sustainable methods for carbon dioxide (CO2) capture are highly sought after. Mature technologies involve chemical reactions that absorb CO2, but they have many drawbacks. Energy-efficient alternatives may be realized by porous physisorbents with void spaces that are complementary in size and electrostatic potential to molecular CO2. Here, we present a robust, recyclable and inexpensive adsorbent termed MUF-16 (MUF = Massey University Framework). This metal-organic framework captures CO2 with a high affinity in its one-dimensional channels. The position of the CO2 molecules sequestered in the framework pores, as determined by X-ray crystallography, illustrate how complementary noncovalent interactions envelop the CO2 while repelling other guest molecules. The low affinity of the MUF-16 pores for these competing gases underpins new benchmarks for the adsorption of CO2 over methane, acetylene, ethylene, ethane, propylene and propane. IAST calculations show that for 50/50 mixtures at 293 K and 1 bar, the CO2/CH4 selectivity is 6690 and the CO2/C2H2 selectivity is 510, for example. Breakthrough gas separations under dynamic conditions benefit from short time lags in the elution of the weakly-adsorbed component to deliver high-purity hydrocarbon products. Ultimately, MUF-16 may be applicable to the removal of CO2 from sources such as natural gas and chemical feedstocks.

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A Universal Porous Adsorbent for the Selective Capture of Carbon Dioxide

10.26434/chemrxiv.9729665.v3 ◽

2019 ◽

Author(s):

Omid Taheri Qazvini ◽

Shane G. Telfer

Keyword(s):

Carbon Dioxide ◽

Noncovalent Interactions ◽

Metal Organic Framework ◽

Time Lags ◽

Atmospheric Concentration ◽

Guest Molecules ◽

Gas Streams ◽

Energy Penalty ◽

Metal Organic ◽

Short Time

Efficient and sustainable methods for carbon dioxide (CO2) capture are essential. Its atmospheric concentration must be reduced to meet climate change targets, and its removal from sources such as chemical feedstocks is vital. While mature technologies involving chemical reactions that absorb CO2 exist, they have many drawbacks. Porous materials with void spaces that are complementary in size and electrostatic potential to CO2 offer an alternative. In these materials, the molecular CO2 guests are trapped by noncovalent interactions, hence they can be recycled by releasing the CO2 with a low energy penalty. Capacity and selectivity are the twin challenges for such porous adsorbents. Here, we show how a metal-organic framework, termed MUF-16 (MUF = Massey University Framework), is a universal adsorbent for CO2 that sequesters large quantities of CO2 from a broad palette of gas streams with record selectivities over competing gases. The crystallographically-determined position of the CO2 molecules captured in the framework pores illustrate how complementary noncovalent interactions envelop CO2 while repelling other guest molecules. The low affinity of the pore environment for other gases underpins the strikingly high selectivity of MUF-16 for CO2 over methane, nitrogen, hydrogen, acetylene, ethylene, ethane, propylene and propane. Breakthrough gas separations under dynamic conditions benefit from short time lags in the elution of the weakly-adsorbed component to deliver a repertoire of high-purity products. MUF-16 is an inexpensive, robust, recyclable adsorbent that is universally applicable to the removal of CO2 from sources such as natural gas, syngas, flue gas and chemical feedstocks.

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A Universal Porous Adsorbent for the Selective Capture of Carbon Dioxide

10.26434/chemrxiv.9729665.v2 ◽

2019 ◽

Author(s):

Omid Taheri Qazvini ◽

Shane G. Telfer

Keyword(s):

Carbon Dioxide ◽

Noncovalent Interactions ◽

Metal Organic Framework ◽

Time Lags ◽

Atmospheric Concentration ◽

Guest Molecules ◽

Gas Streams ◽

Energy Penalty ◽

Metal Organic ◽

Short Time

Efficient and sustainable methods for carbon dioxide (CO2) capture are essential. Its atmospheric concentration must be reduced to meet climate change targets, and its removal from sources such as chemical feedstocks is vital. While mature technologies involving chemical reactions that absorb CO2 exist, they have many drawbacks. Porous materials with void spaces that are complementary in size and electrostatic potential to CO2 offer an alternative. In these materials, the molecular CO2 guests are trapped by noncovalent interactions, hence they can be recycled by releasing the CO2 with a low energy penalty. Capacity and selectivity are the twin challenges for such porous adsorbents. Here, we show how a metal-organic framework, termed MUF-16 (MUF = Massey University Framework), is a universal adsorbent for CO2 that sequesters large quantities of CO2 from a broad palette of gas streams with record selectivities over competing gases. The crystallographically-determined position of the CO2 molecules captured in the framework pores illustrate how complementary noncovalent interactions envelop CO2 while repelling other guest molecules. The low affinity of the pore environment for other gases underpins the strikingly high selectivity of MUF-16 for CO2 over methane, nitrogen, hydrogen, acetylene, ethylene, ethane, propylene and propane. Breakthrough gas separations under dynamic conditions benefit from short time lags in the elution of the weakly-adsorbed component to deliver a repertoire of high-purity products. MUF-16 is an inexpensive, robust, recyclable adsorbent that is universally applicable to the removal of CO2 from sources such as natural gas, syngas, flue gas and chemical feedstocks.

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Tuning the properties of metal–organic framework nodes as supports of single-site iridium catalysts: node modification by atomic layer deposition of aluminium

Faraday Discussions ◽

10.1039/c7fd00031f ◽

2017 ◽

Vol 201 ◽

pp. 195-206 ◽

Cited By ~ 20

Author(s):

Dong Yang ◽

Mohammad R. Momeni ◽

Hakan Demir ◽

Dale R. Pahls ◽

Martino Rimoldi ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Density Functional ◽

Metal Organic Framework ◽

Density Functional Theory Calculations ◽

Atomic Layer ◽

Single Site ◽

Iridium Complexes ◽

Layer Deposition ◽

Metal Organic ◽

Organic Framework

The metal–organic framework NU-1000, with Zr6-oxo, hydroxo, and aqua nodes, was modified by incorporation of hydroxylated Al(iii) ions by ALD-like chemistry with [Al(CH3)2(iso-propoxide)]2 followed by steam (ALD = atomic layer deposition). Al ions were installed to the extent of approximately 7 per node. Single-site iridium diethylene complexes were anchored to the nodes of the modified and unmodified MOFs by reaction with Ir(C2H4)2(acac) (acac = acetylacetonate) and converted to Ir(CO)2 complexes by treatment with CO. Infrared spectra of these supported complexes show that incorporation of Al weakened the electron donor tendency of the MOF. Correspondingly, the catalytic activity of the initial supported iridium complexes for ethylene hydrogenation increased, as did the selectivity for ethylene dimerization. The results of density functional theory calculations with a simplified model of the nodes incorporating Al(iii) ions are in qualitative agreement with some catalyst performance data.

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Density-functional theory models of Fe(iv)O reactivity in metal–organic frameworks: self-interaction error, spin delocalisation and the role of hybrid exchange

Physical Chemistry Chemical Physics ◽

10.1039/d0cp01285h ◽

2020 ◽

Vol 22 (22) ◽

pp. 12821-12830

Author(s):

Fernan Saiz ◽

Leonardo Bernasconi

Keyword(s):

Density Functional Theory ◽

Oxidation Reaction ◽

Density Functional ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Density Functional Theory Calculations ◽

Functional Theory ◽

Metal Organic ◽

Organic Framework

We study the reactivity of Fe(iv)O moieties supported by a metal–organic framework (MOF-74) in the oxidation reaction of methane to methanol using all-electron, periodic density-functional theory calculations.

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Transformation of Cadmium Tetracyanoquinodimethane (TCNQ) into a Cadmium Terephthalate Metal–Organic Framework

Australian Journal of Chemistry ◽

10.1071/ch17187 ◽

2017 ◽

Vol 70 (9) ◽

pp. 973

Author(s):

Manzar Sohail ◽

Farooq Ahmad Kiani ◽

Vedapriya Pandarinathan ◽

Safyan Akram Khan ◽

Damien J. Carter ◽

...

Keyword(s):

Synchrotron Radiation ◽

Photoelectron Spectroscopy ◽

Density Functional ◽

Reaction Pathway ◽

Cyano Group ◽

Metal Organic Framework ◽

Density Functional Theory Calculations ◽

X Ray ◽

X Ray Crystallography ◽

Metal Organic

The transformation of cadmium 7,7,8,8-tetracyanoquinodimethane (TCNQ) into a cadmium terephthalate co-ordination polymer is reported, with the chemistry of this material elucidated using elemental analysis, X-ray photoelectron spectroscopy and synchrotron radiation single-crystal X-ray diffraction. A heptacoordinated CdII linear coordination polymer catena-poly[triaqua-(μ2-benzene-1,4-dicarboxylato-κO,O′)cadmium(ii)]hydrate (1) was isolated while attempting to recrystallize Cd(TCNQ)2. Density functional theory calculations for the oxidation of benzylic carbon attached to the cyano group provided evidence that the reaction pathway proposed herein is highly exergonic and thermodynamically plausible. This structure showed a distorted pentagonal bipyramidal geometry together with a symmetrical mononuclear unit in which each CdII ion is doubly bridged by a dicarboxylato anion. Owing to the softness and minute size of these crystals, this structure had to be elucidated using synchrotron radiation X-ray crystallography.

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A Universal Porous Adsorbent for the Selective Capture of Carbon Dioxide

10.26434/chemrxiv.9729665.v4 ◽

2020 ◽

Author(s):

Omid Taheri Qazvini ◽

Shane G. Telfer

Keyword(s):

Carbon Dioxide ◽

Noncovalent Interactions ◽

Metal Organic Framework ◽

Time Lags ◽

Atmospheric Concentration ◽

Guest Molecules ◽

Gas Streams ◽

Energy Penalty ◽

Metal Organic ◽

Short Time

Efficient and sustainable methods for carbon dioxide (CO2) capture are essential. Its atmospheric concentration must be reduced to meet climate change targets, and its removal from sources such as chemical feedstocks is vital. While mature technologies involving chemical reactions that absorb CO2 exist, they have many drawbacks. Porous materials with void spaces that are complementary in size and electrostatic potential to CO2 offer an alternative. In these materials, the molecular CO2 guests are trapped by noncovalent interactions, hence they can be recycled by releasing the CO2 with a low energy penalty. Capacity and selectivity are the twin challenges for such porous adsorbents. Here, we show how a metal-organic framework, termed MUF-16 (MUF = Massey University Framework), is a universal adsorbent for CO2 that sequesters large quantities of CO2 from a broad palette of gas streams with record selectivities over competing gases. The crystallographically-determined position of the CO2 molecules captured in the framework pores illustrate how complementary noncovalent interactions envelop CO2 while repelling other guest molecules. The low affinity of the pore environment for other gases underpins the strikingly high selectivity of MUF-16 for CO2 over methane, nitrogen, hydrogen, acetylene, ethylene, ethane, propylene and propane. Breakthrough gas separations under dynamic conditions benefit from short time lags in the elution of the weakly-adsorbed component to deliver a repertoire of high-purity products. MUF-16 is an inexpensive, robust, recyclable adsorbent that is universally applicable to the removal of CO2 from sources such as natural gas, syngas, flue gas and chemical feedstocks.

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Observation of an Intermediate to H2 Binding in a Metal–organic Framework

10.26434/chemrxiv.13208207.v1 ◽

2020 ◽

Author(s):

Brandon Barnett ◽

hayden evans ◽

Gregory M. Su ◽

Henry Z. H. Jiang ◽

Romit Chakraborty ◽

...

Keyword(s):

Electrostatic Interactions ◽

Density Functional ◽

Activation Barrier ◽

Metal Organic Framework ◽

Covalent Bond ◽

Density Functional Theory Calculations ◽

Redox Activity ◽

Metal Centers ◽

Metal Organic ◽

Organic Framework

Coordinatively-unsaturated metal sites within certain zeolites and metal–organic frameworks can strongly adsorb various molecules. While many classical examples involve electron-poor metal cations that interact with adsorbates largely through electrostatic interactions, unsaturated electron-rich metal centers housed within porous frameworks can often chemisorb guests amenable to redox activity or covalent bond formation. Despite the promise that materials bearing such sites hold in addressing myriad challenges in gas separations and storage, very few studies have directly interrogated mechanisms of chemisorption at open metal sites within porous frameworks. Here, we show that H2chemisorption at the trigonal pyramidal Cu+sites in the metal–organic framework CuI‑MFU-4l occurs via the intermediacy of a metastable physisorbed precursor species. In situpowder neutron diffraction experiments enable crystallographic characterization of this intermediate, the first time that this has been accomplished for any material. Support for a precursor intermediate is also afforded from temperature-programmed desorption and density functional theory calculations. The activation barrier separating the precursor species from the chemisorbed state is shown to correlate with a change in the Cu+coordination environment that enhances π-backbonding with H2. Ultimately, these findings demonstrate that adsorption at framework metal sites does not always follow a concerted pathway and underscore the importance of probing kinetics in the design of next-generation adsorbents.

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