DOI: 10.1002/cctc.201402499

Evidence of Intracrystalline Mesostructured Porosity inZeolites by Advanced Gas Sorption, Electron Tomographyand Rotation Electron DiffractionJavier Garcia-Martinez,*[a, d] Changhong Xiao,[b] Katie A. Cychosz,[c] Kunhao Li,[a] Wei Wan,[b]

Xiaodong Zou,*[b] and Matthias Thommes*[c]

Introduction

The discovery of the amorphous silicate materials with orderedmesoporosity, such as MCM-41[1] and SBA-15,[2] in the 1990’sraised tremendous interest in such materials for catalytic appli-cations.[3] The large cylindrical mesopores templated by thesurfactant micelles were considered the solution to the diffu-sion problem that limits the performance of the microporouszeolites in many catalytic processes. Compared to the micro-pores of zeolites, these mesopores allow orders-of-magnitudefaster mass transport, which can be truly considered as “molec-ular highways”. However, catalytic conversion of reactant mole-cules (e.g. , petroleum feed) is hindered by the low Brønsted

acidity and inadequate hydrothermal stability inherently relat-ed to the amorphous nature of these materials.[4]

Considerable effort has been devoted to resolving this fun-damental issue during the past 20 years. Among them, the re-cently emerged field of hierarchical zeolites, that is, micropo-rous zeolites with at least another pore system of meso- (2–50 nm) or macro-sizes (>50 nm). These hold special promisebecause they potentially offer the desired fast diffusion, strongzeolitic acidity, and high hydrothermal stability for optimal cat-alytic performance.[5] A unique post-synthetic zeolite meso-structuring process uses cationic surfactants, for example, ce-tyltrimethylammonium bromide (CTAB), the same as that usedin the synthesis of MCM-41, as mesopore templates to intro-duce well-controlled mesoporosity into zeolite crystals. Whilethe process is applicable to many zeolite structures and chemi-cal compositions, significant development and commercializa-tion work was performed first on Y zeolite of faujasite struc-ture, owing to the great technological potential for these ma-terials, especially in catalytic cracking of petroleum, which isone of the largest catalytic applications of zeolites in modernenergy industry.

The mesostructuring process was first demonstrated ona commercial USY zeolite (Zeolyst CBV720).[6] Later it was ex-tended to higher aluminum content NaY zeolite (e.g. , CBV100)by adding an acid de-alumination step before the surfactant-mesostructuring reaction.[7] The mesoporous zeolite Y wasfound to have comparable hydrothermal stability and Brønstedacidity as conventional zeolite Y, even after being subjected tothe typical hydrothermal ultrastabilization treatment for ob-taining USY zeolites and the more severe steaming conditions(e.g. , 788 8C in 100 % steam for 8 h) often used to simulate de-

The small size of micropores (typically <1 nm) in zeolitescauses slow diffusion of reactant and product molecules inand out of the pores and negatively impacts the product selec-tivity of zeolite based catalysts, for example, fluid catalyticcracking (FCC) catalysts. Size-tailored mesoporosity was intro-duced into commercial zeolite Y crystals by a simple surfac-tant-templating post-synthetic mesostructuring process. Theresulting mesoporous zeolite Y showed significantly improvedproduct selectivity in both laboratory testing and refinerytrials. Advanced characterization techniques such as electron

tomography, three-dimensional rotation electron diffraction,and high resolution gas adsorption coupled with hysteresisscanning and density functional theory, unambiguously re-vealed the intracystalline nature and connectivity of the intro-duced mesopores. They can be considered as molecular high-ways that help reactant and product molecules diffuse quicklyto and away from the catalytically active sites within the zeo-lite crystals and, thus, shift the selectivity to favor the produc-tion of more of the valuable liquid fuels at reduced yields ofcoke and unconverted feed.

[a] Prof. J. Garcia-Martinez, Dr. K. LiRive Technology, Inc.1 Deer Park Drive, Monmouth Junction, NJ 08852 (USA)E-mail : j.gracia@ua.es

[b] Dr. C. Xiao, Dr. W. Wan, Prof. X. ZouBerzelii Center EXSELENT on Porous Materialsand Inorganic and Structural ChemistryDepartment of Materials and Environmental ChemistryStockholm University106 91 Stockholm (Sweden)E-mail : xzou@mmk.su.se

[c] Dr. K. A. Cychosz, Dr. M. ThommesQuantachrome Instruments1900 Corporate Drive, Boynton Beach, FL 33426 (USA)E-mail : matthias.thommes@quantachrome.com

[d] Prof. J. Garcia-MartinezMolecular Nanotechnology LabDepartment of Inorganic Chemistry, University of AlicanteCampus de San Vicente, 03690 Alicante (Spain)E-mail : j.garcia@ua.es

Supporting information for this article is available on the WWW underhttp://dx.doi.org/10.1002/cctc.201402499.

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activation of cracking catalysts in a fluid catalytic cracking(FCC) unit.[8] Extensive laboratory testing of the FCC catalystscontaining mesostructured zeolite Y (Meso-Y) and conventionalzeolite Y (Conv-Y) suggested that the FCC catalysts containingMeso-Y would yield significantly higher amounts of transporta-tion fuels, that is, light cycle oil (LCO) and gasoline at reducedcoke and bottoms (unconverted feed) production. This trend ismore evident for cracking of lower quality vacuum gas oil(VGO) feed (Figure 1, see Table S1 in the Supporting Informa-tion for main properties of the feeds). The zeolite Y mesostruc-turing and the corresponding FCC catalyst manufacturing pro-cesses were recently scaled up to commercial quantities. Tworefinery trials were also performed successfully. These months-long trials in two separate North American refineries not onlyconfirmed the excellent hydrothermal and mechanical stabilityof the new catalysts containing Meso-Y, but also the sametrend in product yields as depicted in Figure 1.[9]

Herein we describe the use of several complementary ad-vanced characterization techniques: high resolution physicaladsorption coupled with hysteresis scanning and advancedtheoretical methods based on non-local density functionaltheory (NLDFT), high-resolution electron microscopy imaging,electron tomography (ET), and rotation electron diffraction(RED) to further establish the single-phase nature of the meso-porous zeolites and to gain a more detailed understanding ofthe intracrystalline mesopores and their connectivity. We showthat the unique combination of gas adsorption and electronmicroscopy is capable of giving a comprehensive picture ofthe structure of these zeolites, which can then be related di-rectly back to their performance in catalytic applications.Recent work reported by some other groups suggested thecomposite nature of materials prepared under similar condi-tions.[10] The advanced characterization reported herein isaimed to clarify this open question by providing strong evi-dence for the single-phase nature of the surfactant-templatedmesostructured zeolites prepared under proper conditions.

Results and Discussion

The transmission electron micrographs (TEM) in Figure 2 showthat the large channel-like mesopores in the starting commer-cial zeolite CBV720 were replaced with the uniformly sized anddistributed smaller mesopores, while maintaining the originalcrystal shapes after the mesostructuring treatment, which sup-ports the previously described crystal rearrangement mecha-nism for the mesopore formation.[8a] High resolution (HR)TEMcan provide crystal structure information at atomic resolution.Figure 2 c shows an HRTEM image taken along the [1�11] di-rection indicating the coexistence of ordered micropores anduniformly-sized mesopores. The corresponding Fourier trans-form of the HRTEM image (inset in Figure 2 c) shows that theMeso-Y crystal has a highly crystalline structure with orderedzeolitic micropores (small white features) embedded in a highconcentration of mesopores (larger and uniformly sized anddistributed white features in Figure 2 c). Knowing the fact thatthe contrast of HRTEM images may change by the change ofdefocus values (through contrast transfer function), we per-formed high angle annular dark field scanning transmissionelectron microscopy (HAADF-STEM), which provides Z-contrastimage independent of defocus. The HAADF-STEM image clearlyshows the presence of mesopores with the pore sizes of 2–5 nm (dark features in Figure 2 d).

The templating effect of the surfactant is supported by theexcellent correspondence of the mesopore sizes with the sizesof the surfactant micelles (Figure 3 d). Figure 3 a shows a lineardisplay of the argon (87 K) adsorption isotherms on a series ofthe mesoporous zeolite Y synthesized with alkyltrimethylam-monium surfactants of different sizes (CnH2n+1NMe3

+ , n = 10–22). The isotherms exhibit pore condensation and hysteresis,highlighting the presence of mesopores in these zeolites.Semi-logarithmic plots (Figure 3 b) of the same isotherms clear-ly illustrate pore filling in the low relative pressure range dueto the microporosity. The isotherms represent a combinationof types I and IV isotherms, indicative of micropore fillingbelow relative pressure of 0.1 and pore condensation in themesopores at higher relative pressures. For the smaller meso-pores, reversible pore condensation is observed, analogous to

Figure 1. Advanced cracking evaluation (ACE) testing results comparing two catalysts containing mesostructured USY zeolite to two state-of-the-art catalystswith conventional USY using two different North American refinery feeds: Light VGO feed: Meso-1 (^) and Conv-1 (&) ; Heavy VGO feed: Meso-2 (*) andConv-2 (~) ; all curves were fitted by kinetic lump modeling. a) LCO + Gasoline yields vs. Conversion. b) Coke yields vs. Conversion. c) Bottoms yields vs. Cokeyields.

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what has been observed for M41S materials with pore diame-ters smaller than 4 nm.[11] However, type H1 hysteresis appearsfor larger mesopore diameters obtained by using alkyltrimethy-lammonium surfactants with the alkyl of C16 and higher. Cu-mulative pore volumes (Figure 3 c) and pore-size distributioncurves (Figure 3 d) were calculated from the isotherms by ap-plication of an advanced NLDFT method assuming argon ad-sorption at 87 K in spherical siliceous zeolite pores in the mi-cropore range and cylindrical silica pores in the mesoporerange.[12] The pore-size distributions illustrate the bimodalmicro- and mesopore nature of these zeolites, and also showin a remarkable way the possibility of tailoring the pore sizeand pore volume of mesopores in a given zeolitic framework,while not affecting the micropore-size distribution.

Complementary to gas adsorption,[13] ET is an importanttechnique to study the 3 D distribution and connectivity ofmesopores in zeolites.[14] However, the resolution of ET is limit-ed to a few nanometers and it is not possible to resolve themicropores (<2 nm) in zeolites. The recently developed 3 DRED method[15] can, on the other hand, provide the 3 D struc-ture information at the atomic level.[16] Herein 3 D-RED and 3 D-

ET characterizations are com-bined for the first time to inves-tigate the hierarchical structurefrom atomic to mesoscale of thesame mesostructured Y crystalprepared using C16 surfactant(Figure 4 and Movie S1). Fig-ure 4 a shows that the mesopor-ous Y crystals are of high crystal-linity. The 3 D reciprocal latticereconstructed from the 3 D-REDdata shows that the particle con-tains two sets of crystal latticesof zeolite Y, indicating the pres-ence of twinning (Figure 4 c andMovie S2). The orientation rela-tionship between the twin com-ponents, as well as their orienta-tions in relation to the particle,could be deduced. The tomo-gram reconstructed from the ETimages shows clearly how themesopores are distributedthroughout the crystal(Movie S3). The pore architectureand the connectivity of the mes-opores are intuitively illustratedfrom the reconstructed structuremodel of electron tomography(Figure 4 d, Movie S4).

To study the pore structureand texture of these micro- andmesoporous zeolites in detail,additional advanced gas sorp-tion measurements were per-formed on the C16 Meso-Y

sample. Figure 5 a shows argon and nitrogen adsorption iso-therms at 87 and 77 K, respectively. The argon isotherm wasmeasured over a wide range of relative pressure (from P/P0 =

10�6 to 1) in order to resolve both micropore filling and porecondensation in the mesopores, whereas nitrogen adsorptionwas only measured in the upper relative pressure range where,after the micropores have been already filled, adsorptionoccurs in the mesopores. Applying advanced NLDFT methodsdedicated to argon adsorption and nitrogen adsorption[11b, 17]

leads to the pore-size distribution curves shown in Figure 5 b.The pore-size distribution curves obtained from the argon(87 K) data reveal the expected bimodal pore-size distribution,with micro- and mesopore peaks centered around 1.2 and4.3 nm. Excellent agreement was obtained between the meso-pore-size distributions from the two gases, highlighting theability of these advanced methods to accurately characterizethese zeolitic materials.

Argon adsorption experiments at 77 and 65 K helped furtherelucidate structural details about the micro-mesopore networkcharacteristics of this mesoporous zeolite (Figure 5 c). Perform-ing adsorption experiments at a lower temperature affects the

Figure 2. Transmission electron microscopy (TEM) images. a) EM image of the starting zeolite Y CBV720. b) TEMimage of the Meso-Y showing the uniformly sized and distributed mesopores (lighter spots). Insets in a) andb) magnified views of the white-boxed areas. c) High-resolution TEM image of a Meso-Y crystal taken along the[1�11] direction with the corresponding Fourier transform (inset), which shows that the crystal is a single crystalzeolite Y. d) HAADF-STEM Z-contrast image of another mesostructured zeolite Y crystal. The image was taken ata 2 � 106 magnification, camera length 8 cm, and spot size 0.7 nm.

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thermodynamic state of the confined fluid and leads to hyste-resis in all mesopores including the narrow mesopores smallerthan 4 nm, at which point reversible pore condensation occursfor argon adsorption at 87 K. As shown in Figure 5 c, a combina-tion of types H1 and H2 hysteresis is observed for argon ad-sorption isotherms at 65 and 77 K, that is, the hysteresis loopis parallel with the exception of the characteristic step-down inthe desorption branch at lower relative pressures. This clearlyindicates that the majority of mesopores are freely accessiblewithout constriction (these pores give rise to the type H1 hys-teresis portion), whereas the access to a smaller amount ofmesopores is affected by either constrictions in the form ofpore necks or these pores are only accessible via the narrowzeolitic micropore channels. The emptying of these constrictedpores is associated with the characteristic cavitation step downin the desorption branch.[18] This is further confirmed by analy-sis of hysteresis scanning measurements performed on theargon (77 K) isotherm and shown in Figure 5 d, where only par-tially filling the pore system and then measuring desorption in-dicates that the hysteresis loop at lower relative pressures cor-responds to a cavitation step, because the scanning curvesreturn directly to the desorption boundary curve in the regimeof the characteristic step down.[18b]

Hence, by using the argon desorption data obtained at 65and 87 K in combination with the scanning gas adsorption (at77 K) we have been able to distinguish and quantify two typesof mesoporosity in the hierarchical zeolite for the first time:the majority being the freely accessible mesopores and a small-er fraction only accessible through micropores. Indeed, utiliz-

ing the change in desorbed vol-umes associated with the char-acteristic step-down in the rela-tive pressure ranges below 0.35(for 77 K) and 0.25 (for 65 K),owing to cavitation togetherwith the total mesopore volumeobtained from the argon (87 K)for this zeolite sample, the analy-sis suggests that 36 %(0.08 cm3g�1) of the mesoporevolume is constricted and 64 %(0.15 cm3g�1) of the mesoporevolume is open. The presence ofthe constricted mesoporosity isconsidered an additional evi-dence of the crystal rearrange-ment mechanism for the forma-tion of mesopores. The meso-pores form when the surfactantmolecules self-assemble insidethe framework structure and thecrystal structure rearranges toaccommodate them.[8a] If themesostructuring process stops,due to insufficient surfactant orreaction time, or other reasons,before the micelles can extend

all the way to reach the external surface of the crystals, someconstricted mesopores may form. More detailed investigationis underway to gain deeper understanding of the crystal rear-rangement mechanism, as well as other possible causes to theformation of such constricted mesoporosity.

Conclusion

The presence of intracrystalline and interconnected mesoporesin the mesostructured zeolites produced by the simple surfac-tant-templated approach was unambiguously confirmed bya unique combination of state-of-the-art gas sorption tech-niques, electron tomography and rotation electron diffraction.Under the right conditions, zeolites can undergo structure rear-rangement to accommodate surfactant-templated mesoporosi-ty, while maintaining their main physical and chemical proper-ties. The majority of the highly interconnected mesopores arefreely accessible, serving as networks of “molecular highways”,to significantly enhance intracrystalline diffusion, which led tothe much improved product selectivity observed in the exten-sive lab testing and refinery trials for the mesostructured zeoli-te Y and fluid catalytic cracking (FCC) catalysts. This mesostruc-turing process is applicable to many zeolites of different struc-ture type and chemical compositions. It is reasonable to be-lieve that the “molecular highways” in such mesostructuredzeolites could also provide significant improvement in the per-formance of the catalysts or adsorbents in many processesthat are limited currently by slow mass transport.

Figure 3. Adsorption data of a series of mesostructured CBV720 zeolites. a) Linear and b) semi-logarithmic argonadsorption isotherms at 87 K. c) Cumulative pore volumes and d) NLDFT pore-size distribution curves calculatedfrom the Ar (87 K) isotherms.

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Experimental Section

Zeolite preparation: The zeolites used for the microscopy and ad-vanced gas sorption studies were prepared from a commercial USYzeolite purchased from Zeolyst International (CBV720). In a typicalmesostructuring experiment, 1.0 g of the zeolite was first magneti-cally stirred in 6.25 mL aqueous solution of 0.094 g NaOH and0.5 g of alkyltrimethylammonium (CnH2n + 1 NMe3

+) chloride or bro-mide for 5 min. The reaction mixture was then heated at 353 K for12 h, followed by filtration, washing thoroughly with deionizedwater, and drying in air. All the samples were calcined in static airat 823 K for 5 h to remove the surfactant templates.

Argon and nitrogen physisorption: Adsorption experiments, in-cluding hysteresis scanning experiments, with nitrogen (77.4 K)and argon (87.3 and 77.4 K) were performed by using a Quantach-romeAutosorb-iQ MP. Prior to the sorption experiments, the sam-ples were outgassed for 12 h under turbomolecular pump vacuumat 623 K. The pore-size distribution curves were calculated fromthe isotherms by application of an advanced NLDFT method as-suming argon (or nitrogen) adsorption at 87 K (or 77 K) in spherical

siliceous zeolite pores in the micro-pore range and cylindrical silicapores in the mesopore range.

TEM, STEM-HAADF, electron to-mography, and rotation electrondiffraction: TEM studies were per-formed by using JEOL JEM-2010and JEM-2100F TEM at acceleratingvoltages of 100 or 200 kV. Highangle annular dark field scanningTEM (HAADF-STEM) imaging wasperformed by using a JEOL JEM-2100F TEM at 200 kV. Samples forTEM studies were prepared by dip-ping a sonicated suspension of thesample in ethanol on a LaceyFormvar/Carbon copper grid.

Electron tomography (ET) and rota-tion electron diffraction (RED)[15]

were performed by using a JEOLJEM-2100 TEM at 200 kV. A Gatan912 ultra-high tilt tomographysample holder was used. A tiltseries of bright-field TEM imagesof a mesostructured zeolite Y parti-cle were acquired over an angularrange of about �758 with the in-crement of 18. RED data was col-lected on the same crystals afterelectron tomography by usinga 12-bit Gatan ES500W Erlangshencamera side-mounted at a 35 mmport using the software RED-datacollection. The 3D reciprocal latticewas reconstructed and analyzedusing the software RED - dataprocessing. Alignments of the re-corded TEM images in the tiltseries and the tomogram recon-struction were performed usingthe IMOD software. The segmenta-tion of the tomograms was done

using 3 D Filters Plugin in ImageJ software. The tomograms arebinned in x, y, z directions to facilitate the calculation so that eachvoxel has a size of 0.63 � 0.63 � 0.63 nm, which allows a reasonablesampling of mesopores. To reduce the noise, the reconstructed to-mograms have gone through Median filter with structure elementof size 3 before segmentation. A spot segmentation algorithm wasemployed with seed threshold and local background values adjust-ed to match the contrast between pore and wall in the tomogram.

FCC catalyst preparation, deactivation, and testing: The FCC cat-alysts were prepared from a mesostructured USY zeolite, whichwas manufactured at commercial scale from NaY zeolite, usingspray drying technique. Before the testing, the experimental cata-lysts and the commercial incumbent catalysts used at the twoNorth American refineries were deactivated by Cyclic PropyleneSteaming 1 (CPS-1)[19] procedure at comparable V and Ni loadingsseen in the respective equilibrium catalysts to properly simulatethe actual deactivation of the catalysts in normal refineryoperation.

Figure 4. Rotation electron diffraction (RED) and electron tomography (ET) on the C16 Meso-Y. a) An ED frame inthe rotation electron diffraction (RED) data series. b) The corresponding TEM image in the ET series. c) Reconstruct-ed 3 D reciprocal lattices from the RED data with the reconstructed 3 D morphology of the corresponding particleobtained from electron tomography superimposed. RED data shows that the particle is highly crystalline zeolite Ywith two twin domains (lattices shown in red and green, respectively) sharing a common [111] axis. d) The 3 Dvolume of a part of the tomogram from the area marked in b showing the connectivity of the mesopores inMeso-Y.

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Acknowledgements

The ET and RED work were supported by the Swedish ResearchCouncil (VR), the Swedish Governmental Agency for InnovationSystems (VINNOVA), and the Knut & Alice Wallenberg Foundationthrough the project grant 3DEM-NATUR. The EM facility was alsosupported by the Knut & Alice Wallenberg Foundation. J.G.M. andK.L. would like to acknowledge the contribution of the employees,management, investors, and partners of Rive Technology to thegreat advancement of the mesostructured zeolite technologysince early 2009.

Keywords: catalysis · characterization · cracking · mesoporousmaterials · zeolites

[1] a) C. T. Kresge, M. E. Leonowicz, W. J. Roth, J. C. Vartuli, J. S. Beck, Nature1992, 359, 710 – 712; b) J. S. Beck, J. C. Vartuli, W. J. Roth, M. E. Leono-wicz, C. T. Kresge, K. D. Schmitt, C. T. W. Chu, D. H. Olson, E. W. Shep-pard, J. Am. Chem. Soc. 1992, 114, 10834 – 10843.

[2] D. Zhao, J. Feng, Q. Huo, N. Melosh, G. H. Fredrickson, B. F. Chmelka,G. D. Stucky, Science 1998, 279, 548 – 552.

[3] a) B. Lebeau, A. Galarneau, M. Linden, Chem. Soc. Rev. 2013, 42, 3661 –3662; b) C. T. Kresge, W. J. Roth, Chem. Soc. Rev. 2013, 42, 3663 – 3670;c) J. M. Thomas, Nature 1994, 368, 289 – 290.

[4] a) C. Perego, R. Millini, Chem. Soc. Rev. 2013, 42, 3956 – 3976; b) U.Olsbye, S. Svelle, M. Bjørgen, P. Beato, T. V. W. Janssens, F. Joensen, S.Bordiga, K. P. Lillerud, Angew. Chem. Int. Ed. 2012, 51, 5810 – 5831;Angew. Chem. 2012, 124, 5910 – 5933.

[5] a) D. P. Serrano, J. M. Escola, P. Pi-zarro, Chem. Soc. Rev. 2013, 42,4004 – 4035; b) K. Mçller, T. Bein,Chem. Soc. Rev. 2013, 42, 3689 –3707; c) N. D. Petkovich, A. Stein,Chem. Soc. Rev. 2013, 42, 3721 –3739; d) J. M. Thomas, Phys. Chem.Chem. Phys. 2014, 16, 7647 – 7661.

[6] J. Y. Ying, J. Garcia-Martinez,US20050239634, 2005.

[7] J. Garcia-Martinez, M. M. Johnson,L. Valla, US20100196263, 2010.

[8] a) J. Garc�a-Mart�nez, M. Johnson, J.Valla, K. Li, J. Y. Ying, Catal. Sci.Technol. 2012, 2, 987 – 994; b) J.Garc�a-Mart�nez, K. Li, G. Krishnaiah,Chem. Commun. 2012, 48, 11841 –11843.

[9] a) B. Speronello, J. Garcia-Martinez,A. Hansen, R. Hu, Refin. Oper. 2011,2, 1 – 6; b) G. Krishnaiah, B. Spero-nello, A. Hansen, J. Crosby in Amer-ican Fuels and Petrochemical Mau-facturers Annual Meeting, San Anto-nio, TX, 2013.

[10] a) D. Verboekend, M. Milina, S.Mitchell, J. P�rez-Ram�rez, Cryst.Growth Des. 2013, 13, 5025 – 5035;b) I. I. Ivanova, E. E. Knyazeva,Chem. Soc. Rev. 2013, 42, 3671 –3688.

[11] a) M. Thommes in Nanoporous Ma-terials Science and Engineering(Eds. : G. Q. Lu, X. S. Zhao), WorldScientific, 2004, pp. 317 – 364; b) M.Thommes, Chem. Eng. Tech. 2010,82, 1059 – 1073.

[12] M. Thommes in Introduction to Zeolite Science and Practice (Eds. : J.Cejka, H. van Bekkum, A. Corma), Elsevier, 2007, pp. 495 – 523.

[13] F. Rouquerol, J. Rouquerol, K. S. W. Sing, P. Llewellyn, G. Maurin, Adsorp-tion by Powders and Porous Solids : Princeples, Methodology and Applica-tions, Academic Press, 2013.

[14] a) J. Zecevic, C. J. Gommes, H. Friedrich, P. E. de Jongh, K. P. de Jong,Angew. Chem. Int. Ed. 2012, 51, 4213 – 4217; Angew. Chem. 2012, 124,4289 – 4293; b) P. A. Midgley, E. P. W. Ward, A. B. Hungria, J. M. Thomas,Chem. Soc. Rev. 2007, 36, 1477 – 1494; c) R. Leary, P. A. Midgley, J. M.Thomas, Acc. Chem. Res. 2012, 45, 1782 – 1791.

[15] a) W. Wan, J. Sun, J. Su, S. Hovmoller, X. Zou, J. Appl. Crystallogr. 2013,46, 1863 – 1873; b) D. Zhang, P. Oleynikov, S. Hovmçller, X. Zou, Z. Kris-tallogr. 2010, 225, 94 – 102.

[16] a) R. Matinez-Franco, M. Moliner, Y. Yun, J. Sun, W. Wan, X. Zou, A.Corma, Proc. Natl. Acad. Sci. USA 2013, 110, 3749 – 3754; b) J. Su, E.Kapaca, L. Liu, V. Georgieva, W. Wan, J. Sun, V. Valtchev, S. Hovmçller, X.Zou, Microporous Mesoporous Mater. 2014, 189, 115 – 125; c) T. Willham-mar, Y. Yun, X. Zou, Adv. Funct. Mater. 2014, 24, 182 – 199.

[17] J. Landers, G. Y. Gor, A. V. Neimark, Colloids Surf. A 2013, 437, 3 – 32.[18] a) M. Thommes, B. Smarsly, M. Groenewolt, P. I. Ravikovitch, A. V. Nei-

mark, Langmuir 2006, 22, 756 – 764; b) C. J. Rasmussen, A. Vishnyakov,M. Thommes, B. M. Smarsly, F. Kleitz, A. V. Neimark, Langmuir 2010, 26,10147 – 10157.

[19] L. T. Boock, T. F. Petti, J. A. Rudesill in Deactivation and Testing of Hydro-carbon-Processing Catalysts, Vol. 634, American Chemical Society, 1996,pp. 171 – 183.

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Figure 5. Adsorption data on the C16 Meso-Y. a) Argon (87 K) and nitrogen (77 K) adsorption isotherms. b) NLDFTpore-size distributions calculated from the argon (87 K) and nitrogen (77 K) isotherms. c) Argon adsorption iso-therms at 77 K and 65 K. d) Hysteresis scanning isotherms on the argon (77 K) isotherm.

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FULL PAPERS

J. Garcia-Martinez,* C. Xiao,K. A. Cychosz, K. Li, W. Wan, X. Zou,*M. Thommes*

&& –&&

Evidence of IntracrystallineMesostructured Porosity in Zeolites byAdvanced Gas Sorption, ElectronTomography and Rotation ElectronDiffraction

Advanced characterization by electrontomography, three-dimensional rotationelectron diffraction, and high resolutiongas adsorption coupled with hysteresisscanning and density functional theoryunambiguously revealed the intracystal-line nature and connectivity of the in-troduced mesopores in the surfactant-templated mesostructured zeolite Y.

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