Abstract: The present invention relates to a process for the preparation of a zeolitic material having a CHA-type framework structure comprising YO2 and X2O3, wherein said process comprises the steps of: (1) providing a mixture comprising one or more sources for YO2, one or more sources for X2O3, one or more optionally substituted ethyltrimethylammonium cation-containing compounds, and one or more tetraalkylammonium cation R1R2R3R4N+-containing compounds as structure directing agent; (2) crystallizing the mixture obtained in step (1) for obtaining a zeolitic material having a CHA-type framework structure; wherein Y is a tetravalent element and X is a trivalent element, wherein R1, R2, and R3 independently from one another stand for alkyl, wherein R4 stands for cycloalkyl, and wherein the YO2:X2O3 molar ratio of the mixture in (1) ranges from 2 to 1,000, as well as to zeolitic materials which may be obtained according to the inventive process and to their use.

Abstract: Provided is a metal-containing CHA-type zeolite in which a ratio of a maximum intensity of an absorption peak in a range of 3685 cm?1 or more and 3750 cm?1 or less to a maximum intensity of an absorption peak in a range of 1800 cm?1 or more and 1930 cm?1 or less is less than 1.5 in an IR spectrum. A method for producing the metal-containing CHA-type zeolite includes a metal incorporation step of mixing a metal source and a CHA-type zeolite in which a ratio of a maximum intensity of an absorption peak in a range of 3665 cm?1 or more and 3750 cm?1 or less to a maximum intensity of an absorption peak in a range of 1800 cm?1 or more and 1930 cm?1 or less is less than 1.5 in an IR spectrum.

Abstract: A process for treating gaseous effluents developed in a coffee roasting installation making it possible to treat gaseous effluents developed in a coffee roasting installation, in which the effluents are passed through an oxidative catalytic converter. Within the catalytic converter use is made of a catalyst selected from the group including: a) a catalyst including a porous faujasite support containing copper oxide nanoparticles in a quantity of between 2% and 7% of the total weight of the catalyst; b) a catalyst including a porous ?-alumina support containing copper oxide nanoparticles in a quantity of between 2% and 7% of the total weight of the catalyst; and c) a catalyst including a mesoporous zeolite or silica support containing iron nanoparticles in a quantity of between 2% and 7% of the total weight of the catalyst.

Abstract: Provided is a method for preparing a zeolite having a Si/Al ratio of at least 10 by interzeolite transformation in the absence of an organic structure directing agent. The method is more cost effective and less equipment intensive as it eliminates the costly organic structure directing agent and the waste treatment at the plant.

Abstract: The disclosure describes an exemplary binding layer formed on Aluminum (Al) substrate that binds the substrate with a coated material. Additionally, an extended form of the binding layer is described. By making a solution containing Al-transition metal elements-P—O, the solution can be used in slurry making (the slurry contains active materials) in certain embodiments. The slurry can be coated on Al substrate followed by heat treatment to form a novel electrode. Alternatively, in certain embodiments, the solution containing Al-transition metal elements-P—O can be mixed with active material powder, after heat treatment, to form new powder particles bound by the binder.

Abstract: According to the invention there is provided a zeolite having a porous structure produced by forming the zeolite on a porous carbon substrate which has been substantially or completely removed, wherein (i) the zeolite was formed on the substrate at a loading of at least 8% by weight and/or (ii) the zeolite has a reinforcing layer.

Abstract: A process for isomerizing an aromatic cut containing at least one aromatic compound containing eight carbon atoms per molecule is described, comprising bringing said cut into contact with at least one catalyst comprising at least one metal from group VIII of the periodic classification of the elements, at least one zeolitic support comprising a zeolite selected from zeolites with structure type EUO and MOR, used alone or as a mixture, and at least one matrix, such that the specific surface area of the matrix in the zeolitic support of said catalyst is in the range 5 to 200 m2/g.

Abstract: The invention relates to a process for preparing a hydroconversation catalyst consisting of a modified zeolite Y, comprising the steps of a treatment of a modified zeolite Y by suspension thereof in a basic pH solution, stopping the previous treatment by neutralization of the modified zeolite Y containing solution with an acid-containing solution; filtering and washing the recovered modified zeolite Y solid, drying and optionally calcining the modified zeolite Y solid, placing the modified zeolite Y solid of step d) in contact, with stirring, in an ion exchange solution and optional steaming and/or calcining the modified zeolite Y type compound for obtaining the catalyst containing a modified zeolite Y.

Abstract: The present invention is a phosphorous modified zeolite (A) made by a process comprising in that order: selecting a zeolite with low Si/Al ratio (advantageously lower than 30) among H+ or NH4+-form of MFI, MEL, FER, MOR, clinoptilolite, said zeolite having been made preferably without direct addition of organic template; steaming at a temperature ranging from 400 to 870° C. for 0.01-200 h; leaching with an aqueous acid solution containing the source of P at conditions effective to remove a substantial part of Al from the zeolite and to introduce at least 0.3 wt % of P; separation of the solid from the liquid; an optional washing step or an optional drying step or an optional drying step followed by a washing step; a calcination step.

Abstract: A metal-doped or metal-exchanged zeolite is disclosed, wherein the doping metal is present in the zeolite in the form of individual atoms i.e. as monomeric and/or dimeric species. Further, a process for the preparation of such a metal-doped or metal-exchanged zeolite is disclosed. The metal-doped zeolites are useful, in particular, as catalysts for the reduction of nitrogen oxides.

Abstract: Provided is a beta-type zeolite which has a high catalytic activity and is not easily deactivated. The beta-type zeolite of the invention has a substantially octahedral shape, has a Si/Al ratio of 5 or more, and is a proton-type zeolite. The Si/Al ratio is preferably 40 or more. This beta-type zeolite is preferably obtained by transforming a raw material beta-type zeolite synthesized without using a structure directing agent into an ammonium-type zeolite through ion exchange, then, exposing the beta-type zeolite to water vapor, and subjecting the exposed beta-type zeolite to an acid treatment.

Abstract: The present invention provides a modified Y-type molecular sieve, characterized by having a unit cell size of 2.420-2.440 nm; as percent by weight of the modified Y-type molecular sieve, a phosphorus content of 0.05-6%, a RE2O3 content of 0.03-10%, and an alumina content of less than 22%; and a specific hydroxyl nest concentration of less than 0.35 mmol/g and more than 0.05 mmol/g, said ? ? specific ? ? hydroxyl ? ? nest ? ? concentration = [ ( M 500 ? ° ? ? C . - M 200 ? ° ? ? C . ) - ( 17 / 9 ) × ( M 800 ? ° ? ? C . - M 500 ? ° ? ? C . ) ] × 1000 36 × ( 1 - M 200 ? ° ? ? C . ) × C ? ( Unit ? : ? mmol ? / ? g ) wherein M200° C., M500° C. and M800° C. respectively represent the weight loss percents of a sample measured at 200° C., 500° C. and 800° C., and C is the crystallinity of the sample. The modified Y-type molecular sieve has few defect in the crystal lattice.

Abstract: The invention relates to a process for preparing a catalyst comprising a mesoporized zeolite, comprising the steps of: preparation of a protonic mesoporized zeolite, which contains at least one network of micropores and at least one network of mesopores, and treatment in a gas or liquid phase containing ammonia or ammonium ions. The invention also related to the obtained catalyst and the use of this catalyst in hydroconversion processes.

Abstract: A catalyst for the conversion of oxygenates, such as alcohols or ethers, to olefins consists essentially of a selected SUZ-4 zeolite that has a Si/Al ratio of at least 20, preferably between 20 and 500, especially between 20 and 100. The basic SUZ-4 zeolite is prepared in a manner known per se, whereafter the Si/Al ratio is increased to the desired value. The selected SUZ-4 zeolite catalyst of the invention has a longer life time and a better product selectivity than the conventional/standard SUZ-4 zeolite catalysts.

Abstract: A tin containing zeolitic material having an MWW-type framework structure (Sn-MWW), having a tin content of at most 2 weight-%, calculated as element and based on the weight of the Sn-MWW, and having an X-ray diffraction pattern comprising peaks at 2 theta diffraction angles of (6.6±0.1)°, (7.1±0.1)°, and (7.9±0.1)°.

Abstract: The present invention relates to a process for the preparation of a zeolitic material having a BEA framework structure comprising the steps of: (i) providing one or more zeolitic materials having a BEA framework structure, wherein the BEA framework structure comprises YO2 and X2O3, wherein Y is a tetravalent element, and X is a trivalent element; (ii) subjecting the one or more zeolitic materials provided in step (i) to a procedure for removing at least a portion of X, preferably tetrahedrally coordinated X, from the BEA framework structure; wherein the Y:X molar ratios of the one or more zeolitic materials provided in step (i) are respectively comprised in the range of from 1 to 50.

Abstract: The present invention relates to a process for preparing a phosphorus containing zeolite type catalysts based on crystalline aluminosilicates, the catalysts of this process and the use of this catalysts for the conversion of methanol to olefins.

Abstract: Processes described include reacting a fresh or spent catalyst, or sorbent, with a solution containing an extracting agent (such as an acid or a base). Preferably, the catalyst contains both alumina and a molecular sieve (or a sorbent), and the reaction is performed under relatively mild conditions such that the majority of the base material does not dissolve into the solution. Thus, the catalyst can be re-used, and in certain instances the catalyst performance even improves, with or without re-incorporating certain of the metals back into the catalyst. Additionally, metals contained in the catalyst, such as Na, Mg, Al, P, S, Cl, K, Ca, V, Fe, Ni, Cu, Zn, Sr, Zn Sb, Ba, La, Ce, Pr, Nd, Pb, or their equivalent oxides, can be removed from the catalyst. Some of the metals that are removed are relatively valuable (such as the rare earth elements of La, Ce, Pr and Nd).

Abstract: A method of manufacturing an artificial zeolite. The method includes the steps of: heating a waste insulator to form a molten insulator; quenching and pulverizing the molten insulator; and heat treating the quenched and pulverized insulator in an alkaline aqueous solution.

Abstract: A method of manufacturing a solid acid catalyst using industrial waste such as an insulator, optical fiber, and tip material is provided. The raw material contains a template agent, a compound having a formula of R14COR15, where R14 and R15 are alkyl groups, a silicon-containing inorganic compound, an aluminum-containing inorganic compound, and water with a weight ratio of SiO2/Al2O3 of at least 1,000. The raw material is heat treated in a closed chamber (a first heat treatment), and heat treated in an atmosphere containing oxygen (a second heat treatment).

Abstract: Compositions and methods for preparing mesoporous materials from low Si/Al ratio zeolites. Such compositions can be prepared by acid wash and/or isomorphic substitution pretreatment of low Si/Al ratio zeolites prior to introduction of mesoporosity.

Abstract: The present invention relates to a hydroamination catalyst comprising boron beta zeolites, wherein the hydroamination catalyst is doped with lithium, and also a process for producing it. The present patent application further relates to a process for preparing amines by reaction of ammonia or primary or secondary amines with olefins at elevated temperatures and pressures in the presence of the hydroamination catalyst of the invention.

Abstract: Compositions and methods for preparing mesostructured zeolites having improved hydrothermal stability. Such mesostructured zeolites can be prepared by subjecting a zeolite to rare earth ion exchange prior to and/or subsequent to introducing mesoporosity into the zeolite.

Abstract: A titanium silicate variant named UPRM-5 was prepared using tetraethylammonium hydroxide as a structure-directing agent (SDA). Successful detemplation was achieved via ion exchange with NH4Cl. Effective functionalization was obtained after ion exchanging the detemplated material using SrCl2 and BaCl2. Adsorption of CO2 at 25° C. in Sr- and Ba-UPRM-5 materials activated at different temperatures. For low partial pressures, the observed CO2 adsorption capacities increased as follows: NH4-UPRM-5<Sr-UPRM-5<Ba-UPRM-5. Both the Sr- and Ba-UPRM-5 materials exhibited outstanding selectivity for CO2 over CH4, N2 and O2.

Abstract: A zeolite membrane production apparatus is provided having a reaction container having a support insertion opening for insertion of tubular supports and which houses a reaction solution for formation of zeolite membranes on the surfaces of the supports, a heating means for heating the reaction solution through the reaction container, and a supporting apparatus provided on the reaction container in a freely detachable manner and which supports a plurality of the supports. The inner wall surface of the reaction container has two mutually parallel flat surfaces, the supporting apparatus has a plurality of supporting sections that anchor one end of each of the plurality of supports, and the plurality of supporting sections are provided in the supporting apparatus such that when the supporting apparatus is set in the reaction container, each of the plurality of supports is disposed between the two flat surfaces and parallel to the two flat surfaces.

Abstract: The invention covers a process for obtaining an alkaline earth or rare earth metal-P-modified molecular sieve (M-P-modified molecular sieve) comprising the following steps: a). selecting at least one molecular sieve selected from one of: a P-modified molecular sieve which contains at least 0.3 wt % of P obtained by dealuminating a molecular sieve in a steaming step, followed by a leaching step using an acid solution containing a source of P a molecular sieve which is modified with P during step b) by dealuminating the molecular sieve in a steaming step, followed by a leaching step using an acid solution containing a source of P thereby introducing at least 0.3 wt % of P b). contacting said molecular sieve with an alkaline earth or rare earth metal-containing compound (M-containing compound) to introduce at least 0.05 wt % of the alkaline earth or rare earth metal to the molecular sieve. The invention also covers a catalyst composite comprising: a).

Abstract: Stable, aqueous dispersion containing silicon dioxide powder having a hydroxyl group density of 2.5 to 4.7 OH/nm2, which is obtained from a silicon dioxide powder produced by a flame hydrolysis process under acid conditions. The dispersion is produced by incorporating the silicon dioxide powder into an aqueous solution by means of a dispersing device. The dispersion can be used to produce glass articles.

Abstract: A method of modifying an alkylation catalyst to reduce the formation of condensed hydrocarbon species thereon. The method comprises providing an alkylation catalyst comprising a plurality of active sites. The plurality of active sites on the alkylation catalyst may include a plurality of weakly acidic active sites, intermediate acidity active sites, and strongly acidic active sites. A base is adsorbed to a portion of the plurality of active sites, such as the strongly acidic active sites, selectively poisoning the strongly acidic active sites. A method of modifying the alkylation catalyst by providing an alkylation catalyst comprising a pore size distribution that sterically constrains formation of the condensed hydrocarbon species on the alkylation catalyst or by synthesizing the alkylation catalyst to comprise a decreased number of strongly acidic active sites is also disclosed, as is a method of improving a regeneration efficiency of the alkylation catalyst.

Abstract: The present invention is a phosphorous modified zeolite (A) made by a process comprising in that order: selecting a zeolite with low Si/Al ratio (advantageously lower than 30) among H+ or NH4+-form of MFI, MEL, FER, MOR, clinoptilolite, said zeolite having been made preferably without direct addition of organic template; steaming at a temperature ranging from 400 to 870° C. for 0.01-200 h; leaching with an aqueous acid solution containing the source of P at conditions effective to remove a substantial part of Al from the zeolite and to introduce at least 0.3 wt % of P; separation of the solid from the liquid; an optional washing step or an optional drying step or an optional drying step followed by a washing step; a calcination step.

Abstract: The invention provides a catalyst for catalytically reducing nitrogen oxides in diesel engine exhaust gas by use of unburnt carbon contained in the diesel engine exhaust gas as a reducing agent, the catalyst comprising: (a) an acid zeolite, or (b) an alkali metal- and/or alkaline earth metal-containing zeolite, or (c) a rare earth metal-containing zeolite, or (d) a zeolite containing at least one transition metal selected from Fe, Co, Ni and Cu.

Abstract: A family of crystalline aluminosilicate zeolites designated UZM-8HS and derived from UZM-8 have been synthesized. The aluminum content of the UZM-8HS is lower than that of the starting UZM-8 thus changing its ion exchange capacity and acidity. These UZM-8HS are represented by the empirical formula: M1an+Al(1?x)ExSiy?Oz? and are prepared by treatments such as acid extraction and AFS treatments.

Abstract: A process for easily synthesizing a zeolite substance containing an element having a large ionic radius in the framework at a high ratio. This process comprises the following first to fourth steps: First Step: a step of heating a mixture containing a template compound, a compound containing a Group 13 element of the periodic table, a silicon-containing compound and water to obtain a precursor (A); Second Step: a step of acid-treating the precursor (A) obtained in the first step; Third Step: a step of heating the acid-treated precursor (A) obtained in the second step together with a mixture containing a template compound and water to obtain a precursor (B); and Fourth Step: a step of calcining the precursor (B) obtained in the third step to obtain a zeolite substance.

Abstract: A titanosilicate represented by the following compositional formula (1), wherein in the infrared absorption spectrum measured in the dehydrated state, the absorption spectrum has an absorption band having a relative maximum value at 930±15 cm?1: xTiO2.(1?x)SiO2??Compositional Formula (1) (wherein x is from 0.0001 to 0.2).

Abstract: A family of crystalline aluminosilicate zeolites designated UZM-5HS and derived from UZM-5 have been synthesized. The aluminum content of the UZM-5HS is lower than that of the starting UZM-5 thus changing its ion exchange capacity and acidity. These UZM-5HS are represented by the empirical formula: M1an+Al(1?x)ExSiy?Oz? and are prepared by treatments such as acid extraction and AFS treatments.

Abstract: The invention, in one embodiment, is a method for preparing crystalline zeolites by (a) contacting a calcined essentially aluminum free borosilicate zeolite with an aqueous acid solution, thereby producing an at least partially deboronated zeolite; (b) contacting said at least partially deboronated zeolite with a solution selected from the group consisting of an aqueous aluminum salt solution, thereby producing an aluminosilicate zeolite; an aqueous gallium salt solution, thereby producing a gallosilicate zeolite; an aqueous iron salt solution, thereby producing a ferrosilicate zeolite; and mixtures thereof; and (c) where the contacting in step (b) occurs at a pH of not greater than about 3.5.

Abstract: A family of crystalline aluminosilicate zeolites designated UZM-5HS and derived from UZM-5 have been synthesized. The aluminum content of the UZM-5HS is lower than that of the starting UZM-5 thus changing its ion exchange capacity and acidity.

Abstract: A zeolite of the faujasite structure having a silica to alumina molar ratio (bulk) of greater than about 13, a unit cell size in the range of from 24.10 to 24.40 Å, and a surface area of at least about 875 m2/g as measured by the BET method and ASTM D4365-95 with nitrogen adsorption at p/po values of 0.02, 0.03 and 0.04, is prepared by a combination of hydrothermal and dealumination techniques, and finds use as, for example, an adsorbent for polar and non-polar materials.

Abstract: Zeolites of type A wherein all the cationic sites of which occupied by sodium, calcium and/or magnesium, potassium and hydronium cations, which exhibit the advantage of having a water adsorption capacity≧23%, which do not adsorb and therefore cannot desorb nitrogen, and which, incorporated in polyurethane (PU) resins, make it possible to increase the potlife of the PU formulations in which they are incorporated. Such zeolites are prepared by a process comprising bringing into contact an aqueous suspension of zeolite 3A, 4A or 5A, an aqueous solution of calcium or potassium salt(s) or solutions of calcium and potassium salt(s), and an acid solution, simultaneously or otherwise and in any order; and in then filtering off and washing the solid obtained, and then drying and activating the zeolite.

Abstract: The invention, in one embodiment, is a method for preparing crystalline zeolites by (a) contacting a calcined essentially aluminum free borosilicate zeolite with an aqueous acid solution, thereby producing an at least partially deboronated zeolite; (b) contacting said at least partially deboronated zeolite with a solution selected from the group consisting of an aqueous aluminum salt solution, thereby producing an aluminosilicate zeolite; an aqueous gallium salt solution, thereby producing a gallosilicate zeolite; an aqueous iron salt solution, thereby producing a ferrosilicate zeolite; and mixtures thereof; and (c) where the contacting in step (b) occurs at a pH of not greater than about 3.5.

Abstract: Thin films for use as dielectric in semiconductor and other devices are prepared from silica zeolites, preferably pure silica zeolites such as pure-silica MFI. The films have low k values, generally below about 2.7, ranging downwards to k values below 2.2. The films have relatively uniform pore distribution, good mechanical strength and adhesion, are relatively little affected by moisture, and are thermally stable. The films may be produced from a starting zeolite synthesis or precursor composition containing a silica source and an organic zeolite structure-directing agent such as a quaternary ammonium hydroxide. In one process the films are produced from the synthesis composition by in-situ crystallization on a substrate. In another process, the films are produced by spin-coating, either through production of a suspension of zeolite crystals followed by redispersion or by using an excess of the alkanol produced in preparing the synthesis composition.

Abstract: A zeolite catalyst is described corresponding to an acid form of ITQ-7 zeolite and/or all its possible intergrowths, its method of preparation and its application for the alkylation of aromatics with olefins, alcohols or polyalkylated aromatic compounds. It is considered that the catalyst and the application to which this present invention refers are particularly valuable for the production of cumene.

Abstract: The present invention relates to new crystalline, molecular sieve CIT-6 that has the topology of zeolite beta. CIT-6 can be in an all-silica form, in a form wherein zinc is in the crystal framework, or a form containing silicon oxide and non-silicon oxides. In a preferred embodiment, CIT-6 has a crystal size of less than one micron and a water adsorption capacity of less than 0.05 g/g.

Abstract: The present invention relates to a titanium-silicalite (TS-1) molecular sieve and the method for preparation of the same, wherein each crystallite of said titanium-silicalite molecular sieve has a hollow cavity with a radial length of 5-300 nm. The benzene adsorption capacity of the molecular sieve determined at 25° C. and P/P0=0.10 for 1 hour is at least 70 mg/g; and the method for preparation of said molecular sieve comprises an acid-treatment and then an organic-base treatment of the synthesized TS-1 molecular sieve, or only an organic-base treatment. The TS-1 molecular sieve of the present invention has a relatively high reactivity and activity stability in the catalytic oxidation.

Abstract: The present invention provides a method for preparing a zeolite having lattice substituted heteroatoms. The method includes: (a) contacting a calcined borosilicate zeolite with an acid, thereby producing an at least partially deboronated zeolite; and (b) contacting the at least partially deboronated zeolite with a salt-containing aqueous solution comprising one or more salts selected from the group consisting of aluminum salt, gallium salt, and iron salt, thereby producing a silicate or borosilicate zeolite having a lattice comprising aluminum atoms; gallium atoms, iron atoms or a combination thereof. Step (b) is conducted at a pH of about 3.5 or less. Preferably, step (a), step (b) or both are conducted at a temperature of from about ambient temperature to about 300° C., preferably, under stirring/tumbling.

Abstract: Zeolites of type A wherein all the cationic sites of which occupied by sodium, calcium and/or magnesium, potassium and hydronium cations, which exhibit the advantage of having a water adsorption capacity ≧23%, which do not adsorb and therefore cannot desorb nitrogen, and which, incorporated in polyurethane (PU) resins, make it possible to increase the potlife of the PU formulations in which they are incorporated. Such zeolites are prepared by a process comprising bringing into contact an aqueous suspension of zeolite 3A, 4A or 5A, an aqueous solution of calcium or potassium salt(s) or solutions of calcium and potassium salt(s), and an acid solution, simultaneously or otherwise and in any order; and in then filtering off and washing the solid obtained, and then drying and activating the zeolite.

Abstract: There is disclosed a new form of zeolite beta which shows substantially greater stability and greater catalyst lifetime when used in the alkylation and transalkylation of aromatic compounds. The new, surface-modified zeolite beta is characterized by having surface aluminum 2p binding energies, as measured by X-ray photoelectron spectroscopy, of at least 74.8 electron volts. This surface-modified zeolite beta is prepared by treating an as synthesized and templated zeolite beta with an acid at a pH between about 0 and about 2 at a temperature up to about 125° C. for a time sufficient to modify the chemical environment of the surface aluminum atom without bringing about dealumination of the zeolite beta, then calcining the acid-treated templated material at 550-700° C. to remove the template.

Abstract: Novel synthetic zeolite compositions of extremely small particle sizes that have increased loading capability, and process technology for producing such compositions are described. So far as is presently known, it has never been possible to form such compositions heretofore. The process technology involves, inter alia, contacting the zeolite cake formed in its production with a specified type of treating agent and then subjecting the treated zeolite to physical subdivision.

Abstract: A process for the reduction of ketones or aldehydes to alcohols has been developed. The process involves contacting the ketone or aldehyde with a primary or secondary alcohol and a catalyst at reduction conditions. The catalyst is a molecular sieve having the empirical formula: (MwSnxTiySi1-x-y-zGez)O2 where M is a trivalent metal such as aluminum or boron. These molecular sieves have a microporous three dimensional framework structure of at least SiO2 and SnO2 tetrahedral units, a crystallographically regular pore system and the characteristic x-ray diffraction pattern of zeolite beta.

Abstract: The invention concerns a NU-86 zeolite comprising silicon and at least one element T selected from the group formed by aluminium, iron, gallium and boron, preferably aluminium, characterized in that element T has been extracted from the framework, and in that it has a global Si/T atomic ratio of more than about 20. Element T is extracted from the zeolitic framework (or network) by means of at least one heat treatment, optionally carried out in the presence of steam, followed by at least one acid attack using at least one solution of a mineral or organic acid, or by direct acid attack. The invention also concerns a catalyst comprising the zeolite which is at least partially in its acid form, and the use of the catalyst for the conversion of hydrocarbons, in particular for the oligomerization of olefins.

Abstract: There is disclosed a new form of zeolite beta which shows substantially greater stability and greater catalyst lifetime when used in the alkylation and transalkylation of aromatic compounds. The new, surface-modified zeolite beta is characterized by having surface aluminum 2p binding energies, as measured by X-ray photoelectron spectroscopy, of at least 74.8 electron volts. This surface-modified zeolite beta is prepared by treating an as synthesized and templated zeolite beta with an acid at a pH between about 0 and about 2 at a temperature up to about 125.degree. C. for a time sufficient to modify the chemical environment of the surface aluminum atom without bringing about dealumination of the zeolite beta, then calcining the acid-treated templated material at 550-700.degree. C. to remove the template.