Visualizing Dealumination of a Single Zeolite Domain in a Real‐Life Catalytic Cracking Particle

Kalirai, Sam; Paalanen, Pasi P.; Wang, Jian; Meirer, Florian; Weckhuysen, Bert M.

doi:10.1002/ange.201605215

Cited by 38 publications

(16 citation statements)

References 46 publications

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“…[20,21] Both APT and STXM have been applied to zeolite-based catalysts by a number of research groups, resulting in a significant body of accumulated knowledge. [20,[24][25][26][27][28][29][30][31][32][33][34] However, to the best of our knowledge, there are no reports that correlate results of the two characterization techniques. Herein, we have applied APT and STXM in an integrated fashion to study the same single crystal of a laboratory aged (135,000 mile simulation) sample of copper-exchanged zeolite SSZ-13 (Cu-SSZ-13, CHA framework topology), which is the same sample as we previously studied with APT alone.…”

Section: Introductionmentioning

confidence: 99%

Probing the Location and Speciation of Elements in Zeolites with Correlated Atom Probe Tomography and Scanning Transmission X‐Ray Microscopy

Schmidt

Ravenhorst

et al. 2018

ChemCatChem

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Characterizing materials at nanoscale resolution to provide new insights into structure property performance relationships continues to be a challenging research target due to the inherently low signal from small sample volumes, and is even more difficult for nonconductive materials, such as zeolites. Herein, we present the characterization of a single Cu‐exchanged zeolite crystal, namely Cu‐SSZ‐13, used for NO X reduction in automotive emissions, that was subject to a simulated 135,000‐mile aging. By correlating Atom Probe Tomography (APT), a single atom microscopy method, and Scanning Transmission X‐ray Microscopy (STXM), which produces high spatial resolution X‐ray Absorption Near Edge Spectroscopy (XANES) maps, we show that a spatially non‐uniform proportion of the Al was removed from the zeolite framework. The techniques reveal that this degradation is heterogeneous at length scales from micrometers to tens of nanometers, providing complementary insight into the long‐term deactivation of this catalyst system.

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Section: Introductionmentioning

confidence: 99%

Probing the Location and Speciation of Elements in Zeolites with Correlated Atom Probe Tomography and Scanning Transmission X‐Ray Microscopy

Schmidt

Ravenhorst

et al. 2018

ChemCatChem

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“…Alternatively, the introduction of extra-framework cations, such as Al 3+ and La 3+ , via dealumination or ion exchange can significantly improve the BAS strength due to a synergistic effect between Lewis acid sites (LAS) and nearby BAS 4,17 . Those solid acids have been widely applied in gas-phase cracking, such as fluid catalytic cracking processes 26 . However, extra-framework cations can easily leach out from solid acids during the liquid-phase reactions 27 .…”

mentioning

confidence: 99%

Acidity enhancement through synergy of penta- and tetra-coordinated aluminum species in amorphous silica networks

Wang

Jiang

et al. 2020

Nat Commun

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Amorphous silica-aluminas (ASAs) are widely used in acid-catalyzed C-H activation reactions and biomass conversions in large scale, which can be promoted by increasing the strength of surface Brønsted acid sites (BAS). Here, we demonstrate the first observation on a synergistic effect caused by two neighboring Al centers interacting with the same silanol group in flame-made ASAs with high Al content. The two close Al centers decrease the electron density on the silanol oxygen and thereby enhance its acidity, which is comparable to that of dealuminated zeolites, while ASAs with small or moderate Al contents provide mainly moderate acidity, much lower than that of zeolites. The ASAs with enhanced acidity exhibit outstanding performances in C-H bond activation of benzene and glucose dehydration to 5-hydroxymethylfurfural, simultaneously with an excellent calcination stability and resistance to leaching, and they offer an interesting potential for a wide range of acid and multifunctional catalysis.

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“…This is smaller than the previously reported values of zeolite domain size measured in similar FCC particles using CFM ( % 500 nm), [16c] Super-resolution Optical Fluctuation Imaging (SOFI) ( % 500 nm) [17a] and Scanning Transmission X-ray Microscopy (STXM) ( % 400 nm). [21] See SI section S3 for a discussion of the spatial resolution of TEFL measurements. These results show that the high spatial resolution as well as surface sensitivity offered by TEFL can successfully 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 identify, localize the evaluate acidity and reactivity within single zeolite domains in a FCC particle.…”

Section: Nanoscale Chemical Imaging Of a Single Catalyst Particle Witmentioning

confidence: 99%

Nanoscale Chemical Imaging of a Single Catalyst Particle with Tip‐Enhanced Fluorescence Microscopy

et al. 2018

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Determining the active site in real‐life solid catalysts remains an intellectual challenge and is crucial for exploring the road towards their rational design. In recent years various micro‐spectroscopic methods have revealed valuable structure‐activity data at the level of a single catalyst particle, even under reaction conditions. Herein, we introduce Tip‐Enhanced FLuorescence (TEFL) microscopy as a novel and versatile characterization tool for catalysis research. This has been achieved using a Fluid Catalytic Cracking (FCC) catalyst as showcase material. Thin sectioning of industrially used FCC particles together with selective staining of Brønsted acidity has enabled high‐resolution TEFL mapping of different catalyst regions. Hyperspectral information gained via TEFL microscopy reveals a spatial distribution of Brønsted acidity within individual zeolite domains in different regions of the FCC catalyst particle. Comparison of TEFL measurements from different FCC particles showed significant intra‐ and inter‐particle heterogeneities both in zeolite domain size and chemical reactivity.

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Visualizing Dealumination of a Single Zeolite Domain in a Real‐Life Catalytic Cracking Particle

Cited by 38 publications

References 46 publications

Probing the Location and Speciation of Elements in Zeolites with Correlated Atom Probe Tomography and Scanning Transmission X‐Ray Microscopy

Probing the Location and Speciation of Elements in Zeolites with Correlated Atom Probe Tomography and Scanning Transmission X‐Ray Microscopy

Acidity enhancement through synergy of penta- and tetra-coordinated aluminum species in amorphous silica networks

Nanoscale Chemical Imaging of a Single Catalyst Particle with Tip‐Enhanced Fluorescence Microscopy

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