The crystal structure of the zeolite ferrierite
01 Dec 1966-Acta Crystallographica (International Union of Crystallography (IUCr))-Vol. 21, Iss: 6, pp 983-990
About: This article is published in Acta Crystallographica.The article was published on 1966-12-01. It has received 257 citations till now. The article focuses on the topics: Ferrierite & Zeolite.
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TL;DR: In this article, the authors present a review of zeolite nomenclature and propose a method for the recognition of separate species in topologically distinctive compositional series in which different extra-framework cations are the most abundant in atomic proportions.
Abstract: This report embodies recommendations on zeolite nomenclature approved by the International Mineralogical Association Commission on New Minerals and Mineral Names. In a working definition of a zeolite mineral used for this review, interrupted tetrahedral framework structures are accepted where other zeolitic properties prevail, and complete substitution by elements other than Si and Al is allowed. Separate species are recognized in topologically distinctive compositional series in which different extra-framework cations are the most abundant in atomic proportions. To name these, the appropriate chemical symbol is attached by a hyphen to the series name as a suffix except for the names harmotome. pollucite and wairakite in the phillipsite and analcime series. Differences in space-group symmetry and in order-disorder relationships in zeolites having the same topologically distinctive framework do not in general provide adequate grounds for recognition of separate species. Zeolite species are not to be distinguished solely on Si:Al ratio except for heulandite (Si:Al or =4.0). Dehydration, partial hydration, and over-hydration are not sufficient grounds for the recognition of separate species of zeolites. Use of the term "ideal formula" should be avoided in referring to a simplified or averaged formula of a zeolite. Newly recognized species in compositional series are as follows: brewsterite-Sr, -Ba: chabazite-Ca, -Na, -K; clinoptilolite-K, -Na, -Ca; dachiardite-Ca, -Na; erionite-Na, -K, -Ca: faujasite-Na, -Ca, -Mg; ferrierite-Mg, -K, -Na; gmelinite-Na, -Ca, -K; heulandite-Ca, -Na, -K, -Sr; levyne-Ca, -Na; paulingite-K, -Ca; phillipsite-Na, -Ca, -K; stilbite-Ca, -Na. Key references, type locality, origin of name, chemical data, IZA structure-type symbols, space-group symmetry, unit-cell dimensions, and comments on structure are listed for 13 compositional series. 82 accepted zeolite mineral species, and three of doubtful status. Herschelite, leonhardite, svetlozarite, and wellsite are discredited as mineral species names. Obsolete and discredited names are listed.
397 citations
TL;DR: The siting and distribution of framework Al atoms dramatically affect catalytic activity/selectivity both of protonic and transition metal ion-containing zeolite catalysts.
Abstract: Siting of Al atoms in the framework T sites, in zeolite rings and channel/cavity system, and the distribution of Al atoms between single Al atoms and close Al atoms in various Al-O-(Si-O)n-Al sequences in Si-rich zeolites represent key parameters controlling properties of counter ion species. Framework Al siting and distribution is not random or controlled by simple rules and depends on the conditions of the zeolite synthesis. Al in Al-O-(Si-O)2-Al in one 6-MR and single Al atoms predominate in Si-rich zeolites and their population can be varied to a large extent. The siting and distribution of framework Al atoms dramatically affect catalytic activity/selectivity both of protonic and transition metal ion-containing zeolite catalysts.
345 citations
TL;DR: The most attractive achievements in the rational synthesis of multipore zeolites, containing small to extra-large pores, are described, and the improvements reported for relevant chemical processes when these multiporeZeolites have been used as catalysts are described.
Abstract: Financial support by the Spanish Government-MINECO through “Severo Ochoa” (SEV 2012-0267), Consolider Ingenio 2010-Multicat, MAT2012-37160, MAT2012-31657 and Intramural-201480I015 is acknowledged.
259 citations
TL;DR: This review will restrict its interest to molecular dynamics (MD) simulation of zeolites to illustrate this powerful technique and outline results and problems in its application to these complex systems.
Abstract: It is very important to understand the relation between the structure of a zeolite and the adsorption and fate of specific molecules. In this review, we will restrict our interest to molecular dynamics (MD) simulation of zeolites. Our goal is to illustrate this powerful technique and outline results and problems in its application to these complex systems. We shall not follow a chronological order, because the studies in this field are devoted to different phenomena occurring in zeolites, which will be treated separately. The basic features of the MD simulation technique are illustrated first. The application to zeolites of closely related simulation techniques like the Monte Carlo (MC) method (refs 7−11 are recent examples) will not be treated, because the review would become cumbersome and too complex, and we do not feel sufficiently involved in this field.
240 citations
TL;DR: A hybrid method to study problems that involve both bond rearrangements and van-der-Waals interactions is proposed, designed for a reaction between a small or medium sized substrate molecule and a very large chemical system.
Abstract: We propose use of a hybrid method to study problems that involve both bond rearrangements and van-der-Waals interactions. The method combines second-order Moller–Plesset perturbation theory (MP2) calculations for the reaction site with density functional theory (DFT) calculations for a large system under periodic boundary conditions. Hybrid MP2:DFT structure optimisation for a cluster embedded in the periodic model is the first of three steps in a multi-level approach. The second step is extrapolation of the MP2 energy to the complete basis set limit. The third step is extrapolating the high-level (MP2) correction to the limiting case of the full periodic structure. This is done by calculating the MP2 correction for a series of cluster models of increasing size, fitting an analytic expression to these energy corrections, and applying the fitted expression to the full periodic structure. We assume that, up to a constant, the high-level correction is described by a damped dispersion expression. Combining the results of all three steps yields an estimate of the MP2 reaction energy for the full periodic system at the complete basis set level. The method is designed for a reaction between a small or medium sized substrate molecule and a very large chemical system. For adsorption of isobutene in zeolite H-ferrierite, the energies obtained for the formation of different structures, the π-complex, the isobutoxide, the tert-butoxide, and the tert-butyl carbenium ion, are −78, −73, −48, and −21 kJ mol−1, respectively. This corresponds to corrections of the pure DFT (PBE functional) results by −62, −70, −67, and −29 kJ mol−1, respectively. Hence, the MP2 corrections are substantial and, perhaps more importantly, not the same for the different hydrocarbon species in the zeolite. Coupled-cluster (CCSD(T)) calculations change the MP2 energies by −4 kJ mol−1 (tert-butyl cation) or less (below ±1 kJ mol−1 for the other species).
227 citations