NMR Crystallography Reveals Carbonate Induced Al‐Ordering in ZnAl Layered Double Hydroxide

Radhakrishnan, Sambhu; Lauwers, Karl; Chandran, C. Vinod; Trébosc, Julien; Sree, Sreeprasanth Pulinthanathu; Martens, Johan A.; Taulèlle, Francis; Kirschhock, Christine; Breynaert, Eric

doi:10.1002/chem.202101275

Cited by 11 publications

(13 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 ppm lower shift and different sign of the Haeberlen chemical shift anisotropy, D, than carbonate in the interlayer of both LDH and in sodium (bi)carbonate (Table S8, ESI †). This agrees with a recent study of ZnAl-LDH, which based on Rietveld refinement of PXRD data 19 obtained three possible monoclinic structures similar to 1M with one to three crystallographic inequivalent carbon sites, depending on the model and carbonate orientation. However, only a single 13 C resonance was observed experimentally for carbonate for the ZnAl-LDH investigated.…”

Section: Experimental Nmr Resultssupporting

confidence: 92%

“…Recently, a combination of Rietveld refinement of PXRD data and multi-nuclear SSNMR also confirmed a lowering of the space group symmetry to monoclinic for ZnAl-LDH with carbonate in the interlayer. 19 Furthermore, both carbonate and bicarbonate (HCO 3 − ) have been identified in the interlayer of diamagnetic MgAl-LDH, where the high Al content (high cation layer charge) favours carbonate. 15 These two anions can be distinguished based on a 10 ppm difference in the 13 C isotropic chemical shift, δ iso ( 13 C), opposite signs of the 13 C chemical shift anisotropy and assignment based on a visual comparison with the 13 C MAS NMR spectra of sodium carbonate and bicarbonate in MgAl-LDH 15 and calcinated MgAl-LDH.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Unravelling the effect of paramagnetic Ni²⁺on the¹³C NMR shift tensor for carbonate in Mg_2−xNi_xAl layered double hydroxides by quantum-chemical computations

Mohan,

Andersen,

Mareš

et al. 2023

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

Section: Experimental Nmr Resultssupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Unravelling the effect of paramagnetic Ni²⁺on the¹³C NMR shift tensor for carbonate in Mg_2−xNi_xAl layered double hydroxides by quantum-chemical computations

Mohan,

Andersen,

Mareš

et al. 2023

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…NMR has the unique ability to probe the coordination environment and dynamics of NMR active cations. − By now it has become clear that the alkali cation affects all aspects of zeolite formation. , It impacts the distribution of aluminosilicate species in the solution and selects the most stable framework topology. With 23 Na, 39 K, and 133 Cs NMR, the degree of cations in the ion-paired state with oligomers versus hydrated cations in solution can be quantified (Figure ).…”

Section: In Situ Characterization Of Zeolite Crystallization In Hsil ...mentioning

confidence: 99%

Illuminating the Black Box: A Perspective on Zeolite Crystallization in Inorganic Media

Asselman,

Kirschhock,

Breynaert

2023

Acc. Chem. Res.

Self Cite

View full text Add to dashboard Cite

Conspectus Since the discovery of synthetic zeolites in the 1940s and their implementation in major industrial processes involving adsorption, catalytic conversion, and ion exchange, material scientists have targeted the rational design of zeolites: controlling synthesis to crystallize zeolites with predetermined properties. Decades later, the fundamentals of zeolite synthesis remain largely obscured in a black box, rendering rational design elusive. A major prerequisite to rational zeolite design is to fully understand, and control, the elementary processes governing zeolite nucleation, growth, and stability. The molecular-level investigation of these processes has been severely hindered by the complex multiphasic media in which aluminosilicate zeolites are typically synthesized. This Account documents our recent progress in crystallizing zeolites from synthesis media based on hydrated silicate ionic liquids (HSIL), a synthesis approach facilitating the evaluation of the individual impacts of synthesis parameters such as cation type, water content, and alkalinity on zeolite nucleation, growth, and phase selection. HSIL-based synthesis allows straightforward elucidation of the relationship between the characteristics of the synthesis medium and the properties and structure of the crystalline product. This assists in deriving new insights in zeolite crystallization in an inorganic aluminosilicate system, thus improving the conceptual understanding of nucleation and growth in the context of inorganic zeolite synthesis in general. This Account describes in detail what hydrated silicate ionic liquids are, how they form, and how they assist in improving our understanding of zeolite genesis on a molecular level. It describes the development of ternary phase diagrams for inorganic aluminosilicate zeolites via a systematic screening of synthesis compositions. By evaluating obtained crystal structure properties such as framework composition, topology, and extraframework cation distributions, critical questions are dealt with: Which synthesis variables govern the aluminum content of crystallizing zeolites? How does the aluminum content in the framework determine the expression of different topologies? The crucial role of the alkali cation, taking center stage in all aspects of crystallization, phase selection, and, by extension, transformation is also discussed. New criteria and models for phase selection are proposed, assisting in overcoming the need for excessive trial and error in the development of future synthesis protocols. Recent progress in the development of a toolbox enabling liquid-state characterization of these precursor media has been outlined, setting the stage for the routine monitoring of zeolite crystallization in real time. Current endeavors on and future needs for the in situ investigation of zeolite crystallization are highlighted. Finally, experimentally accessible parameters providing opportunities for modeling zeolite nucleation and growth are identified. Overall, this work provides a perspective ...

show abstract

“…Better understanding of the structure and degree of ordering would improve prediction of LDH properties. Theoretically, Me(II) and Me(III) in the hydroxide layers can be perfectly ordered at certain Me(II)/Me(III) ratios, for example, 2 and 3, but the actual arrangement has been reported to range from fully ordered to disordered or a mixture of the two (e.g., refs − ). For example, a seminal study interpreted that order developed when Me(II) and Me(III) had comparable ion size but later work showed that order can also develop in unequally matched Me(II/III) such as Mg(II) and Al(III) in hydrotalcite .…”

Section: Introductionmentioning

confidence: 99%

Order and Disorder in Layered Double Hydroxides: Lessons Learned from the Green Rust Sulfate─Nikischerite Series

Dideriksen

Voigt

Mangayayam

et al. 2022

ACS Earth Space Chem.

View full text Add to dashboard Cite

Layered double hydroxides (LDHs) occur naturally and are synthesized for catalysis, drug delivery, and contaminant remediation. They consist of Me(II)–Me(III) hydroxide sheets separated by hydrated interlayers and weakly held anions. Often, LDHs are nanocrystalline, and sheet stacking and Me(II)–Me(III) arrangement can be disordered, which influences the reactivity and complicates structural characterization. We have used pair distribution function (PDF) analysis to provide detailed information about local and medium range order (≤9 nm) and to determine the structure of synthetic Fe(II)–Fe(III)/Al(III) LDH. The data are consistent with ordered Me(II) and Me(III) in hydroxide sheets, where structural coherence along the c axis decreases with increasing Al content. The PDF for Fe(II)–Al(III) LDH (nikischerite) is best matched by a pattern for a single metal hydroxide sheet. Parallel to decreased structural coherence between layers, coherence within layers decreased to ∼6 nm for synthetic nikischerite. Thus, the length scale of atomic ordering decreased within and between the sheets, resulting in mosaic crystals with coherent scattering domains decreasing in all directions. The high density of grain boundary terminations would affect reactivity. Based on classical nucleation theory and the Kossel crystal growth model, we propose that loss of structural coherence stems from increased supersaturation and the presence of Al-hydroxides during the formation of the Al-rich LDH.

show abstract

NMR Crystallography Reveals Carbonate Induced Al‐Ordering in ZnAl Layered Double Hydroxide

Abstract: Supporting information for this article is given via a link at the end of the document.

Cited by 11 publications

References 48 publications

Unravelling the effect of paramagnetic Ni²⁺on the¹³C NMR shift tensor for carbonate in Mg_2−xNi_xAl layered double hydroxides by quantum-chemical computations

Unravelling the effect of paramagnetic Ni²⁺on the¹³C NMR shift tensor for carbonate in Mg_2−xNi_xAl layered double hydroxides by quantum-chemical computations

Illuminating the Black Box: A Perspective on Zeolite Crystallization in Inorganic Media

Order and Disorder in Layered Double Hydroxides: Lessons Learned from the Green Rust Sulfate─Nikischerite Series

Contact Info

Product

Resources

About

NMR Crystallography Reveals Carbonate Induced Al‐Ordering in ZnAl Layered Double Hydroxide

Abstract: Supporting information for this article is given via a link at the end of the document.

Cited by 11 publications

References 48 publications

Unravelling the effect of paramagnetic Ni2+on the13C NMR shift tensor for carbonate in Mg2−xNixAl layered double hydroxides by quantum-chemical computations

Unravelling the effect of paramagnetic Ni2+on the13C NMR shift tensor for carbonate in Mg2−xNixAl layered double hydroxides by quantum-chemical computations

Illuminating the Black Box: A Perspective on Zeolite Crystallization in Inorganic Media

Order and Disorder in Layered Double Hydroxides: Lessons Learned from the Green Rust Sulfate─Nikischerite Series

Contact Info

Product

Resources

About

Unravelling the effect of paramagnetic Ni²⁺on the¹³C NMR shift tensor for carbonate in Mg_2−xNi_xAl layered double hydroxides by quantum-chemical computations

Unravelling the effect of paramagnetic Ni²⁺on the¹³C NMR shift tensor for carbonate in Mg_2−xNi_xAl layered double hydroxides by quantum-chemical computations