Early discoveries in zeolite chemistry and catalysis at Union Carbide, and follow-up in industrial catalysis

Rabó, Jule A.; Schoonover, Michael W.

doi:10.1016/s0926-860x(01)00840-7

Cited by 93 publications

(39 citation statements)

References 14 publications

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“…In particular, the FCC and hydrocracking in the presence of H 2 gas are extremely important chemical process since huge amounts of heavy hydrocarbon feedstocks are cracked into more valuable fractions. In classical cracking process, zeolite Y has been used as one of the efficient acid catalysts, showing high catalytic activity [7,111]. However, the conventional Y zeolite with big crystal size has very low mass transport efficiency, which resulted in the quick catalytic deactivation during the cracking reaction.…”

Section: Hydrocarbon Crackingmentioning

confidence: 99%

Hierarchically Nanoporous Zeolites and Their Heterogeneous Catalysis: Current Status and Future Perspectives

Somorjai

2014

Catal Lett

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The research field of hierarchically nanoporous zeolites has been growing at an enormous pace over the past decades. Hierarchically nanoporous zeolites have versatile structural properties such as high surface area and large pore volume that can alleviate diffusional limitations of conventional zeolites with solely microporous framework. In this review, various synthesis strategies to hierarchically nanoporous zeolites and their structural advantages in catalytic reactions will be reviewed. In the first part, many novel synthetic approaches for hierarchically nanoporous zeolites such as post-demetallation, softtemplating, hard-templating, and dual-pore-generating surfactant-directed methods will be introduced. In the second part, catalytic applications of hierarchically nanoporous zeolites on various chemical reactions involving isomerization, cracking, alkylation and oxidation will be discussed. The present comprehensive review will provide future opportunities and perspectives on the research of hierarchically nanoporous zeolites including their applications to catalytic reactions.

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Section: Hydrocarbon Crackingmentioning

confidence: 99%

Hierarchically Nanoporous Zeolites and Their Heterogeneous Catalysis: Current Status and Future Perspectives

Somorjai

2014

Catal Lett

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“…[1,2] There has been considerable interest in the scientific world to generate a variety of these porous structures in order to diversify their applications. [3][4][5] The crystal structure and, consequently, the crystals utility, is heavily dependent upon a multitude of synthesis parameters such as temperature, gel precursors, aging, pH, organic templates and so forth.…”

Section: Introductionmentioning

confidence: 99%

Evolution of Surface Morphology with Introduction of Stacking Faults in Zeolites

John

Stevens

Terasaki

et al. 2010

Chemistry A European J

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This paper sets out to try to determine some of the nanoscopic details of template action in zeolites. The problem has been addressed by monitoring the effects of competitive templating using, in particular, atomic force microscopy and high-resolution scanning electron microscopy. Using these techniques, it is possible to determine the subtle crystal growth changes that occur as a result of altering the concentration of these competitive templating agents. This work concerns the two important intergrowth systems MFI-MEL and FAU-EMT. It was found that some organic templating agents provide much greater structure-directing specificity. So much so in the case of the MFI-MEL system that a 2 mol% doping with the highly specific tetrapropylammonium cation drastically changes the fundamental growth processes. Furthermore, the effect of template crowding is shown to reduce specificity. This work shows how extensive frustrated intergrowth structures can still be accommodated within a nominal zeolite single crystal.

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“…The XRD patterns of the zeolite samples and SSA measurements (Table 1), show that they were highly crystalline and retained their structural integrity to a high degree (relative crystallinity above 85% for all the samples except H-X) after the ion exchange procedure. The large structural breakdown observed in the H-X sample is a common phenomenon among the H-forms of zeolites with low Si/Al ratio, attributed to framework instability due to high concentration of acid sites [44]. SEM images of all the zeolites of this work (except again H-X) showed clear phases of zeolitic particles consisting of typical small-sized (<1 lm) X and USY crystals (Fig.…”

Section: Compositional Structural and Acidicmentioning

confidence: 59%

Propane Reactions over Faujasite Structure Zeolites Type-X and USY: Effect of Zeolite Silica over Alumina Ratio, Strength of Acidity and Kind of Exchanged Metal Ion

et al. 2007

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In this work we prepared various zeolite-X and USY samples partially exchanged with copper, iron and platinum. These samples were characterized by XRD, Chemical Analysis, SEM-EDS, N 2 -adsorption-desorption, ammonia-TPD, and tested as catalysts in high temperature (400 and 550°C) propane transformation. The obtained results revealed the strong effect of Si/Al ratio in faujasite zeolite structure, the number and strength of acid sites and of the presence of different metal ions in countered ion sites, on the catalytic activity and selectivity of zeolite-X and USY. The highest propane dehydrogenation activity was achieved with the platinum-exchanged X zeolite (~11.2% propylene yield,~31% selectivity). On the contrary USY zeolites showed high cracking capability and relatively low dehydrogenation activity excepting the platinum-exchanged sample which yielded notably high aromatization products.

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Early discoveries in zeolite chemistry and catalysis at Union Carbide, and follow-up in industrial catalysis

Cited by 93 publications

References 14 publications

Hierarchically Nanoporous Zeolites and Their Heterogeneous Catalysis: Current Status and Future Perspectives

Hierarchically Nanoporous Zeolites and Their Heterogeneous Catalysis: Current Status and Future Perspectives

Evolution of Surface Morphology with Introduction of Stacking Faults in Zeolites

Propane Reactions over Faujasite Structure Zeolites Type-X and USY: Effect of Zeolite Silica over Alumina Ratio, Strength of Acidity and Kind of Exchanged Metal Ion

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