Dataset for "Intrinsic flexibility of the EMT zeolite framework under pressure"

Dataset for "Intrinsic flexibility of the EMT zeolite framework under pressure"

A collection of the data used, and reported in the article "Intrinsic flexibility of the EMT zeolite framework under pressure". This includes high pressure powder X-ray diffraction data collected on the ID15B and ID27 beamlines at the European Synchrotron Radiation Facility (ESRF). It also includes the data from first-principles comparative DFT and lattice-dynamics calculations to calculate the lattice energy and vibrational entropy of the EMT and FAU frameworks. The purpose of this research was to gain a more coherent understanding as to the role of the organic additive 18-crown-6 ether to differentiate between synthesis of EMT and FAU-type zeolites. From the results, it is demonstrated that the 18-crown-6 ether molecule plays a crucial role in the free-energy of crystallisation, driving the framework assembly process towards the EMT topology.

Keywords:
zeolite, framework materials, EMC-2, crystallisation, EMT, FAU, high pressure, X-ray diffraction, DFT, flexibility window, compressibility, lattice dynamics
Subjects:

Cite this dataset as:
Nearchou, A., Cornelius, M., Skelton, J., 2019. Dataset for "Intrinsic flexibility of the EMT zeolite framework under pressure". University of Bath Research Data Archive. https://doi.org/10.15125/BATH-00560.

Export

Data

EMT%20High-Pres ... 0Repository.zip
application/zip (11MB)
Creative Commons: Attribution 4.0

Creators

Antony Nearchou
University of Bath

Mero-Lee Cornelius
University of the Western Cape

Contributors

Zoe Jones
Contributor
University of Bath

Andrew Cairns
Contributor
Imperial College London

Ines Collings
Contributor
European Synchrotron Radiation Facility

Paul Raithby
Project Leader
University of Bath

Stephen Wells
Contributor
University of Bath

Asel Sartbaeva
Project Leader
University of Bath

University of Bath
Rights Holder

Coverage

Collection date(s):

From 1 January 2016 to 31 July 2018

Documentation

Data collection method:

The high pressure X-ray diffraction data within this archive was collected on the ID15B and ID27 beamlines at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The data collection process was as follows: The samples were first loaded into diamond-anvil cells (DACs), suspending in a non-penetrating pressure-transmitting medium (PTM) alongside a ruby chip. On the ID15B beamline, the PTM used was Daphne 7373 oil, the incident X-ray radiation was of wavelength 0.4113 A (Angstroms), and calibrations were performed using silicon. As for the ID27 beamline, the PTM used was silicone oil, the incident X-ray radiation of wavelength 0.3738 A, and calibrations performed with cerium dioxide (CeO2). The DAC pressure was increased in gradual steps, with three 2D diffraction images taken at each pressure step. The pressure was recorded by exciting the ruby chip with a laser and determining the shift of the R1 emission line. The pressure was recorded before and after each pressure point, with an average calculated. The sample was compressed until pressure-induced amorphisation was seen to be imminent. Following this the samples were decompressed to ambient conditions, with several diffraction images taken during the this cycle. Concerning the computational modelling, density-functional theory (DFT) calculations were performed on the empty FAU and EMT framework structures using the plane-wave pseudopotential code VASP. The PBEsol generalised-gradient approximation functional, including the semi-empirical DFT-D3 dispersion correction (PBEsol+D3) were used to determine the quantum-mechanical exchange and correlation. Plane-wave basis augmented-wave (PAW) pseudopotentials of the O 2s/2p and Si 3s/3p electrons in the valence shells were used to represent the electronic structures of the relevant atoms. The PAW projection was performed in real space, and the structures fully optimised. The influence of solvent molecules occupying the framework cages was calculated using the implicit-solvent VASPsol model. Bulk moduli was obtained by compressing/expanding the optimised structures by 1% volume increments, and re-optimising at fixed volumes before fitting the energy/volume curves to the Birch-Murnaghan equations of state. Lattice-dynamics calculations were performed on the optimised structures using the Phonopy package, with a finite-displacement step size of 10^-2 A. To calculate the phonon density of states (DoS) curves, the phonon frequencies were interpolated onto a regular Γ-centered grid of q-points, with 24x24x24 subdivisions. The simulated infrared spectra were calculated using the density-functional perturbation theory (DEPT) routines in VASP, within the open-source SpectroscoPy package. Calculations of the phonon frequencies, elastic constants and Born changes, the PAW projection was applied in reciprocal space.

Data processing and preparation activities:

Before analysis of the high-pressure diffraction data, the 2D diffraction images were processed in the following way. The three images taken at each pressure point were averaged using the FIT2D software, producing an average image. The area of the 2D image was subsequently integrated over in the Dioptas software, to produce a 1D diffraction pattern. This produced the .xy files found in this archive. The .xy files were used in the TOPAS Academic software using Pawley refinements in order to calculate the unit cell parameters at each pressure point. First the refinement at ambient conditions was performed, with subsequent refinements performed using the Batch mode. In this mode, the refinement process is iterative, meaning the input structure for each pressure point is the output from the automated refinement from the previous pressure point. For both the filled and empty zeolite EMC-2 samples the P63/mmc space group was used in the Pawley refinements. The bulk moduli were determined using the PASCal webtool, using data within the 0-2.2 GPa range. The data was fit to the 2nd order Birch-Murnaghan equation of state, weighted using the estimated 0.1 GPa pressure error within the DACs.

Additional information:

The relevant article and dataset include the flexibility window of the EMT framework (filled and empty) simulated using the GASP software. These geometric simulations have been performed previously, and are referenced in "Methodology link" below.

Documentation Files

readme.txt
text/plain (6kB)
Creative Commons: Attribution 4.0

Funders

Engineering and Physical Sciences Research Council (EPSRC)
https://doi.org/10.13039/501100000266

Applying Long-Lived Metastable States in Switchable Functionality via Kinetic Control of Molecular Assembly
EP/K004956/1

Engineering and Physical Sciences Research Council (EPSRC)
https://doi.org/10.13039/501100000266

Multiscale Tuning of Interfaces and Surfaces for Energy Applications
EP/P007821/1

Engineering and Physical Sciences Research Council (EPSRC)
https://doi.org/10.13039/501100000266

Materials Chemistry High End Computing Consortium
EP/L000202/1

Transfer from Oxford to Bath of RS Fellowship
UF090287

Transfer from Oxford to Bath of RS Fellowship
UF090287

Transfer from Oxford to Bath of RS Fellowship
UF090287

Transfer from Oxford to Bath of RS Fellowship
UF090287

Renewal of RS Fellowship
UF140623

Publication details

Publication date: 12 February 2019
by: University of Bath

Version: 1

DOI: https://doi.org/10.15125/BATH-00560

URL for this record: https://researchdata.bath.ac.uk/id/eprint/560

Related articles

Nearchou, A., Cornelius, M.-L., Skelton, J., Jones, Z., Cairns, A., Collings, I., Raithby, P., Wells, S. and Sartbaeva, A., 2019. Intrinsic Flexibility of the EMT Zeolite Framework under Pressure. Molecules, 24(3), p.641. Available from: https://doi.org/10.3390/molecules24030641.

Contact information

Please contact the Research Data Service in the first instance for all matters concerning this item.

Contact person: Antony Nearchou

Departments:

Faculty of Engineering & Design
Chemical Engineering

Faculty of Science
Chemistry

Research Centres & Institutes
Centre for Nanoscience and Nanotechnology
Centre for Sustainable Chemical Technologies