Enhancement of Proton Conductivity in Nonporous Metal-Organic Frameworks: The Role of Framework Proton Density and Humidity

Simona Pili; Peter Rought; Daniil I. Kolokolov; Longfei Lin; Ivan Da Silva; Yongqiang Cheng; Christopher Marsh; Ian P. Silverwood; Victoria García Sakai; Ming Li; Jeremy J. Titman; Lyndsey Knight; Luke L. Daemen; Anibal J. Ramirez-Cuesta; Chiu C. Tang; Alexander G. Stepanov; Sihai Yang; Martin Schröder

doi:10.1021/acs.chemmater.8b02765

Enhancement of Proton Conductivity in Nonporous Metal-Organic Frameworks: The Role of Framework Proton Density and Humidity

Simona Pili, Peter Rought, Daniil I. Kolokolov, Longfei Lin, Ivan Da Silva, Yongqiang Cheng, Christopher Marsh, Ian P. Silverwood, Victoria García Sakai, Ming Li, Jeremy J. Titman, Lyndsey Knight, Luke L. Daemen, Anibal J. Ramirez-Cuesta, Chiu C. Tang, Alexander G. Stepanov, Sihai Yang, Martin Schröder

Research output: Contribution to journal › Article › peer-review

61 Scopus citations

Abstract

Owing to their inherent pore structure, porous metal-organic frameworks (MOFs) can undergo postsynthetic modification, such as loading extra-framework proton carriers. However, strategies for improving the proton conductivity for nonporous MOFs are largely lacking, although increasing numbers of nonporous MOFs exhibit promising proton conductivities. Often, high humidity is required for nonporous MOFs to achieve high conductivities, but to date no clear mechanisms have been experimentally identified. Here we describe the new materials MFM-550(M), [M(HL¹)], (H₄L¹ = biphenyl-4,4′-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), MFM-550(Ba), [Ba(H₂L¹)], and MFM-555(M), [M(HL²)], (H₄L² = benzene-1,4-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), and report enhanced proton conductivities in these nonporous materials by (i) replacing the metal ion to one with a lower oxidation state, (ii) reducing the length of the organic ligand, and (iii) introducing additional acidic protons on the MOF surface. Increased framework proton density in these materials can lead to an enhancement in proton conductivity of up to 4 orders of magnitude. Additionally, we report a comprehensive investigation using in situ ²H NMR and neutron spectroscopy, coupled with molecular dynamic modeling, to elucidate the role of humidity in assembling interconnected networks for proton hopping. This study constructs a relationship between framework proton density and the corresponding proton conductivity in nonporous MOFs, and directly explains the role of both surface protons and external water in assembling the proton conduction pathways.

Original language	English
Pages (from-to)	7593-7602
Number of pages	10
Journal	Chemistry of Materials
Volume	30
Issue number	21
DOIs	https://doi.org/10.1021/acs.chemmater.8b02765
State	Published - Nov 13 2018
Externally published	Yes

Funding

We thank EPSRC (EP/I011870), ERC (AdG 742041), Royal Society and University of Manchester for funding. We are especially grateful to STFC and ISIS Neutron Facility for access to the Beamline IRIS, to Diamond Light Source for access to Beamline I11 and to ORNL for access to Beamline VISION. The computing resources were made available through the VirtuES and ICEMAN projects, funded by Laboratory Directed Research and Development program at ORNL. DIK and AGS acknowledge financial support within the framework of the budget project #AAAA-A17-117041710084-2 of the Boreskov Institute of Catalysis.

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1021/acs.chemmater.8b02765

Cite this

Pili, S., Rought, P., Kolokolov, D. I., Lin, L., Da Silva, I., Cheng, Y., Marsh, C., Silverwood, I. P., García Sakai, V., Li, M., Titman, J. J., Knight, L., Daemen, L. L., Ramirez-Cuesta, A. J., Tang, C. C., Stepanov, A. G., Yang, S., & Schröder, M. (2018). Enhancement of Proton Conductivity in Nonporous Metal-Organic Frameworks: The Role of Framework Proton Density and Humidity. Chemistry of Materials, 30(21), 7593-7602. https://doi.org/10.1021/acs.chemmater.8b02765

@article{cdec8eeab4e648a6af0c87714fb12993,

title = "Enhancement of Proton Conductivity in Nonporous Metal-Organic Frameworks: The Role of Framework Proton Density and Humidity",

abstract = "Owing to their inherent pore structure, porous metal-organic frameworks (MOFs) can undergo postsynthetic modification, such as loading extra-framework proton carriers. However, strategies for improving the proton conductivity for nonporous MOFs are largely lacking, although increasing numbers of nonporous MOFs exhibit promising proton conductivities. Often, high humidity is required for nonporous MOFs to achieve high conductivities, but to date no clear mechanisms have been experimentally identified. Here we describe the new materials MFM-550(M), [M(HL1)], (H4L1 = biphenyl-4,4′-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), MFM-550(Ba), [Ba(H2L1)], and MFM-555(M), [M(HL2)], (H4L2 = benzene-1,4-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), and report enhanced proton conductivities in these nonporous materials by (i) replacing the metal ion to one with a lower oxidation state, (ii) reducing the length of the organic ligand, and (iii) introducing additional acidic protons on the MOF surface. Increased framework proton density in these materials can lead to an enhancement in proton conductivity of up to 4 orders of magnitude. Additionally, we report a comprehensive investigation using in situ 2H NMR and neutron spectroscopy, coupled with molecular dynamic modeling, to elucidate the role of humidity in assembling interconnected networks for proton hopping. This study constructs a relationship between framework proton density and the corresponding proton conductivity in nonporous MOFs, and directly explains the role of both surface protons and external water in assembling the proton conduction pathways.",

author = "Simona Pili and Peter Rought and Kolokolov, {Daniil I.} and Longfei Lin and {Da Silva}, Ivan and Yongqiang Cheng and Christopher Marsh and Silverwood, {Ian P.} and {Garc{\'i}a Sakai}, Victoria and Ming Li and Titman, {Jeremy J.} and Lyndsey Knight and Daemen, {Luke L.} and Ramirez-Cuesta, {Anibal J.} and Tang, {Chiu C.} and Stepanov, {Alexander G.} and Sihai Yang and Martin Schr{\"o}der",

note = "Publisher Copyright: {\textcopyright} 2018 American Chemical Society.",

year = "2018",

month = nov,

day = "13",

doi = "10.1021/acs.chemmater.8b02765",

language = "English",

volume = "30",

pages = "7593--7602",

journal = "Chemistry of Materials",

issn = "0897-4756",

publisher = "American Chemical Society",

number = "21",

}

Pili, S, Rought, P, Kolokolov, DI, Lin, L, Da Silva, I, Cheng, Y, Marsh, C, Silverwood, IP, García Sakai, V, Li, M, Titman, JJ, Knight, L, Daemen, LL, Ramirez-Cuesta, AJ, Tang, CC, Stepanov, AG, Yang, S & Schröder, M 2018, 'Enhancement of Proton Conductivity in Nonporous Metal-Organic Frameworks: The Role of Framework Proton Density and Humidity', Chemistry of Materials, vol. 30, no. 21, pp. 7593-7602. https://doi.org/10.1021/acs.chemmater.8b02765

TY - JOUR

T1 - Enhancement of Proton Conductivity in Nonporous Metal-Organic Frameworks

T2 - The Role of Framework Proton Density and Humidity

AU - Pili, Simona

AU - Rought, Peter

AU - Kolokolov, Daniil I.

AU - Lin, Longfei

AU - Da Silva, Ivan

AU - Cheng, Yongqiang

AU - Marsh, Christopher

AU - Silverwood, Ian P.

AU - García Sakai, Victoria

AU - Li, Ming

AU - Titman, Jeremy J.

AU - Knight, Lyndsey

AU - Daemen, Luke L.

AU - Ramirez-Cuesta, Anibal J.

AU - Tang, Chiu C.

AU - Stepanov, Alexander G.

AU - Yang, Sihai

AU - Schröder, Martin

PY - 2018/11/13

Y1 - 2018/11/13

N2 - Owing to their inherent pore structure, porous metal-organic frameworks (MOFs) can undergo postsynthetic modification, such as loading extra-framework proton carriers. However, strategies for improving the proton conductivity for nonporous MOFs are largely lacking, although increasing numbers of nonporous MOFs exhibit promising proton conductivities. Often, high humidity is required for nonporous MOFs to achieve high conductivities, but to date no clear mechanisms have been experimentally identified. Here we describe the new materials MFM-550(M), [M(HL1)], (H4L1 = biphenyl-4,4′-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), MFM-550(Ba), [Ba(H2L1)], and MFM-555(M), [M(HL2)], (H4L2 = benzene-1,4-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), and report enhanced proton conductivities in these nonporous materials by (i) replacing the metal ion to one with a lower oxidation state, (ii) reducing the length of the organic ligand, and (iii) introducing additional acidic protons on the MOF surface. Increased framework proton density in these materials can lead to an enhancement in proton conductivity of up to 4 orders of magnitude. Additionally, we report a comprehensive investigation using in situ 2H NMR and neutron spectroscopy, coupled with molecular dynamic modeling, to elucidate the role of humidity in assembling interconnected networks for proton hopping. This study constructs a relationship between framework proton density and the corresponding proton conductivity in nonporous MOFs, and directly explains the role of both surface protons and external water in assembling the proton conduction pathways.

AB - Owing to their inherent pore structure, porous metal-organic frameworks (MOFs) can undergo postsynthetic modification, such as loading extra-framework proton carriers. However, strategies for improving the proton conductivity for nonporous MOFs are largely lacking, although increasing numbers of nonporous MOFs exhibit promising proton conductivities. Often, high humidity is required for nonporous MOFs to achieve high conductivities, but to date no clear mechanisms have been experimentally identified. Here we describe the new materials MFM-550(M), [M(HL1)], (H4L1 = biphenyl-4,4′-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), MFM-550(Ba), [Ba(H2L1)], and MFM-555(M), [M(HL2)], (H4L2 = benzene-1,4-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), and report enhanced proton conductivities in these nonporous materials by (i) replacing the metal ion to one with a lower oxidation state, (ii) reducing the length of the organic ligand, and (iii) introducing additional acidic protons on the MOF surface. Increased framework proton density in these materials can lead to an enhancement in proton conductivity of up to 4 orders of magnitude. Additionally, we report a comprehensive investigation using in situ 2H NMR and neutron spectroscopy, coupled with molecular dynamic modeling, to elucidate the role of humidity in assembling interconnected networks for proton hopping. This study constructs a relationship between framework proton density and the corresponding proton conductivity in nonporous MOFs, and directly explains the role of both surface protons and external water in assembling the proton conduction pathways.

UR - http://www.scopus.com/inward/record.url?scp=85056604299&partnerID=8YFLogxK

U2 - 10.1021/acs.chemmater.8b02765

DO - 10.1021/acs.chemmater.8b02765

M3 - Article

AN - SCOPUS:85056604299

SN - 0897-4756

VL - 30

SP - 7593

EP - 7602

JO - Chemistry of Materials

JF - Chemistry of Materials

IS - 21

ER -

Enhancement of Proton Conductivity in Nonporous Metal-Organic Frameworks: The Role of Framework Proton Density and Humidity

Abstract

Funding

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this