Abstract: There are herein disclosed an L-type zeolite catalyst which is obtainable by supporting a platinum component, one or more halogen components and one or more metal components selected from the group Ib of the periodic table on an L-type zeolite, the support amount of one or more metal components selected from the group Ib being in the range of 0.001 to 3% by weight based on the total weight of the catalyst in terms of the metal, a molar ratio of one or more metal components selected from the group Ib/platinum being in the range of 0.01 to 1; and a method for producing aromatic hydrocarbons or a gasoline having a high octane number which comprises the step of bringing one or more fractions selected from a C6 fraction, a C7 fraction, and a C8.sup.+ fraction into contact with this catalyst.

Abstract: A catalytic material is provided which effectuates the aromatization, reformation, and dehydrogenation of aliphatic, cycloaliphatic, and mixtures of aliphatic and cycloaliphatic hydrocarbons. The catalyst comprises an L-zeolite associated with a Group VIII metal such as platinum and having a rare earth metal ion incorporated therein. A method of using the catalytic material is also provided.

Abstract: A catalyst composition and an ethylbenzene isomerization process are disclosed. The composition comprises a silylated zeolite and a promoter comprising a Group VIII metal. The process comprises contacting a fluid which comprises ethylbenzene and at least one xylene with the catalyst composition under a condition sufficient to effect the conversion of ethylbenzene to a xylene. Also disclosed is a process for producing the catalyst composition.

Abstract: A full boiling hydrocarbon feed is reformed to enhance para-xylene and benzene yields. First, the hydrocarbon feed is separated into a C.sub.5- cut, a C.sub.6 -C.sub.7 cut, and a C.sub.8+ cut. The C.sub.6 -C.sub.7 cut has less than 5 lv. % of C.sub.8+ hydrocarbon, and the C.sub.8+ cut has less than 10 lv. % of C.sub.7- hydrocarbon. The C.sub.6 -C.sub.7 cut is subjected to catalytic aromatization at elevated temperatures in a first reformer in the presence of hydrogen and using a non-acidic catalyst comprising at least one Group VIII metal and a non-acidic zeolite support to produce a first reformate stream; and the C.sub.8+ cut is subjected to catalytic aromatization at elevated temperatures in a second reformer in the presence of hydrogen and using an acidic catalyst comprising at least one Group VIII metal and a metallic oxide support to produce a second reformate stream. Less than 20 wt. % of the total amount of C.sub.

Abstract: A process for converting hydrocarbons into aromatic compounds, which entails contacting a composition containing hydrocarbons with a catalyst under temperature and pressure conditions to produce the aromatic compounds, the catalyst containing a matrix of .eta. transition alumina and/or .gamma. transition alumina. The catalyst contains 0.001 to 2 wt % of silicon, 0.1 to 15 wt % of at least one platinum group metal, and 0.005 to 10 wt % of at least one promoter metal. The promoter metals may be tin, germanium, indium, gallium, thallium, antimony, lead, rhenium, manganese, chromium, molybdenium or tungsten. The catalyst may also contain a doping metal.

Abstract: The invention concerns NU-88 zeolite, characterized by:i) a chemical composition with the following formula, expressed in terms of the mole ratios of the oxides for the anhydrous state:100 XO.sub.2, mY.sub.2 O.sub.3, pR.sub.2/n Owherem is 10 or less;p is 20 or less;R represents one or more cations with valency n;X represents silicon and/or germanium;Y represents one or more of the following elements: aluminium, iron, gallium, boron, titanium, vanadium, zirconium, molybdenum, arsenic, antimony, chromium and manganese; andii) an X ray diffraction diagram, in its as synthesized state, which comprises the results shown in Table 1 of the description.The invention also concerns the preparation of the zeolite, any catalyst containing the zeolite and any catalytic process using such a catalyst.

Abstract: A catalyst composition contains a zeolite, cerium or cerium oxide, and a Group VIII metal or metal oxide. The composition is produced by contacting the zeolite with compounds of the metals and then heat-treating the metals-containing zeolite. Hydrocarbons are converted to C.sub.6 -C.sub.8 aromatic hydrocarbons by contacting the hydrocarbons with the catalyst composition at conversion conditions.

Abstract: Gasolines are reformed and parafin and naphthene hydrocarbons are converted to aromatic compounds by contacting the hydrocarbons with a catalyst comprising a matrix of .eta. transition alumina and .gamma. transition alumina. The catalyst contains at least one doping metal, at least one halogen, at least one noble metal and at least one promoter metal. The doping metals are selected from titanium, zirconium, hafnium, cobalt, nickel, zinc, and the lanthanides and the promoter metals are selected from tin, germanium, indium, gallium, thallium, antimony, lead, rhenium, manganese, chromium, molybdenum and tungsten.

Abstract: A dehydrocyclo-oligomerization process is provided for converting aliphatic hydrocarbons to aromatics by contacting the feedstock under conversion conditions which a zeolite bound zeolite catalyst. The zeolite bound zeolite catalyst comprises first zeolite crystals which are bound together by second zeolite crystals. If the zeolite bound zeolite catalyst is selectivated, the process can produce greater than equilibrium amounts of paraxylene.

Abstract: A process for the conversion of a hydrocarbon load containing paraffin, naphthene and aromatic hydrocarbons having 5 to 12 carbon atoms into aromatic compounds, which entails contacting the load with a catalyst under temperature and pressure conditions to produce the aromatic compounds, the catalyst containing:a matrix consisting of 0 to 100% by weight of .eta. transition alumina, the remaining weight percentage of the matrix, up to 100%, consisting of .gamma. transition alumina, andat least one doping metal selected from the group consisting of alkali metals and alkaline-earth metals,at least one halogen selected from the group consisting of fluorine, chlorine, bromine and iodine,at least one noble metal selected from the platinum group, andat least one promoter metal selected from the group consisting of tin, germanium, indium, gallium, thallium, antimony, lead, rhenium, manganese chromium, molybdenum and tungsten,the catalyst having previously been hydrothermally treated at a temperature of 300 to 1,000.

Abstract: Hydrocarbon conversion processes are described which use a sulfur tolerant catalyst system. The catalyst is tolerant to large amounts (about 30,000 ppm sulfur) in the feedstream and comprises a first component which comprises at least one Group VIII metal dispersed on an inorganic oxide support and a second component comprising a metal phthalocyanine dispersed on an inorganic oxide support. Preferred Group VIII metals are platinum and palladium, while preferred metal phthalocyanines are cobalt or nickel phthalocyanine. Preferred inorganic oxide supports are molecular sieves, aluminas and mixtures thereof. Processes which can be carried out using this catalyst system include reforming, hydrocracking, dehydrogenation and isomerization.

Abstract: The present invention describes a process for the conversion of a lower alkane or a mixture of lower alkanes or a feed containing lower alkane(s) to aromatics or higher hydrocarbons, which comprises (i) treating a bifunctional pentasil zeolite catalyst, optionally containing one or more transition elements, having strong dehydrogenation and acid sites with a mixture of H.sub.2, steam and optionally the presence of an inert gas at a gas hourly space velocity of at least about 500 cm.sup.3 g.sup.-1 h.sup.-1 at a temperature in the range of 400.degree.-800.degree. C. and pressure in the range of 1-5 atm. for a period of at least 0.5 h; (ii) treating the catalyst obtained in step (i) with air or O.sub.2 at a gas hourly space velocity of at least about 200 cm.sup.3 g.sup.-1 h.sup.-1) at a temperature in the range of 400-800.degree. C. and pressure in the range of 1-5 atm for a period of at least 0.

Abstract: The feedstock to an aromatization process is processed by a selective adsorption step to remove hydrocarbon species, particularly indan, which have a severe adverse effect on aromatization catalyst stability. The feedstock preferably is a paraffinic raffinate from aromatics extraction. The intermediate from the adsorption step is particularly suitable for the selective conversion of paraffins to aromatics using a high-activity dehydrocyclization catalyst with high aromatics yields and long catalyst life.

Abstract: A reforming process, selective for the dehydrocyclization of paraffins to aromatics, is effected using a catalyst containing a uniformly distributed platinum-group metal component, a surface-layer metal component comprising one ore more of the Group IVA metals and indium and a nonacidic large-pore molecular sieve. The use of this bed of catalyst results in greater selectivity of conversion of paraffins to aromatics and in improved catalyst stability.

Abstract: In the present invention, dimethylbutanes are removed from the raffinate component of the feed to a dehydrocyclization process. Thus, according to a preferred embodiment, a process is provided for producing aromatics by the following steps:(a) contacting fresh paraffins rich feed hydrocarbons, containing 0.1 to 20.0 wt. % dimethylbutanes with a highly selective dehydrocyclization catalyst in a reaction zone, under dehydrocyclization reaction conditions, to convert paraffins to aromatics and obtain an aromatics rich effluent;(b) separating aromatics from the effluent to obtain an aromatics lean raffinate;(c) removing dimethyl butanes from the raffinate to obtain a raffinate of reduced dimethylbutane content; and(d) recycling the raffinate of reduced dimethylbutane content to the reaction zone.Preferably, the dehydrocyclization catalyst used is a nonacidic, monofunctional catalyst. Platinum on L zeolite is a particularly preferred highly selective dehydrocyclization catalyst for use in the process.

Abstract: A catalyst composition and a process for using of the catalyst composition in a hydrocarbon conversion process are disclosed. The composition comprises an inorganic support, a Group VA metal or metal oxide, and optionally a Group IVA metal or metal oxide and a Group VIII metal or metal oxide. The process comprises contacting a fluid which comprises at least one saturated hydrocarbon with the catalyst composition under a condition sufficient to effect the conversion of the hydrocarbon to an olefin. Also disclosed is a process for producing the catalyst composition.

Abstract: A novel ruthenium-phosphine complex useful as a catalyst for asymmetric hydrogenation is disclosed, which is represented by formula (I):{RuCl(R-BINAP)}{Ru(EtNH.sub.2)(R-BINAP)}(.mu.-Cl).sub.3 (I)wherein Et stands for an ethyl group; and R-BINAP represents a tertiary phosphine represented by formula (II): ##STR1## wherein R represents a hydrogen atom or a methyl group.

Abstract: A reforming process, selective for the dehydrocyclization of paraffins to aromatics, is effected using a catalyst containing multiple Group VIII (8-10) noble metals having different gradients within the catalyst and a nonacidic large-pore molecular sieve. The use of this bed of catalyst results in greater selectivity of conversion of paraffins to aromatics and improved catalyst stability, particularly in the presence of small amounts of sulfur.

Abstract: A catalyst and process is described for aromatizing one or more C.sub.3 to C.sub.6 saturated hydrocarbon to a product low in methane and essentially containing ethane or ethane and propane and aromatic hydrocarbons. A partially sulfided, Pt/Re loaded, essentially hydrogen-form, crystalline aluminosilicate molecular sieve exhibiting the MFI structure and having a Si/Al ratio between about 40 and about 600 is shown to have an excellent catalyst lifetime and favor low methane production, high conversion and high selectivity to benzene, toluene and xylenes and ethane or ethane and propane.

Abstract: New compositions of matter comprise a metal from the group consisting of platinum, rhodium and palladium, a metal from the first row of Group VIII of the Periodic Table and a nonacidic L-zeolite. A preferred composition is Pt--Ni/KL-zeolite. Such catalysts are prepared by coimpregnation of the zeolite with the metals. Methods of using the catalysts in reforming, aromatization or dehydrogenation are provided.

Abstract: By this invention there is provided a catalyst composition comprising a Group IVB oxide, an amorphous silica-alumina support having dispersed thereon a rare earth oxide, which as herein used also includes yttrium oxide, and a metal(s) selected from the group consisting of Group VIII noble metal(s), mixtures of Group VIII noble metal(s) and tin, mixtures of Group VIII noble metal(s) and rhenium, and mixtures of Group VIII noble metal(s), tin and rhenium. The amorphous silica-alumina support contains at least about 50% silica by weight. The catalyst can function as a hydrocarbon conversion catalyst in reactions where platinum on halided (Cl,F)-alumina is typically used.

Abstract: A process for efficiently producing dimethylnaphthalene by a single-step reaction which comprises cyclizing dehydrogenating 5-tolyl-penta-2-ene in the presence of a catalyst comprising in combination (a) a solid acid such as crystalline aluminosilicate, silica-alumina or alumina; (b) a noble metal such as palladium and platinum; and a carrier such as carbon, silicon oxide, titanium oxide and zirconium oxide. The process results in simplification of production, effective utilization of reaction heat and rationalization of the heat balance.

Abstract: Catalytically cracked naphthas containing C.sub.9 + hydrocarbons are hydrocracked over a crystalline zeolite, typically, mildly steamed zeolite beta then subjected to reforming to achieve a gasoline product of reduced end boiling range and higher octane than the feed. A hydrogen stream from the reformer which contains a catalytic promoter, such as chlorine, is separated into a first stream and a second stream. The first stream is treated over a solid sorbent to remove the promoter and recycled promoter to the hydrocracking step while the untreated second hydrogen stream which contains promoter is recycled to the reformer.

Abstract: Provided is a reforming process for producing a high purity benzene product using a non-acidic zeolitic catalyst. The high purity benzene is extracted from a light fraction of reformate that has less than 500 ppm by weight toluene. Generally, a hydrocarbon feed is reformed in a reformer under reforming conditions in the presence of a non-acidic catalyst to produce a reformate. That reformate is separated into a light fraction and a heavy fraction. The extraction unit, preferably an extractive distillation unit, is then used to separate the light fraction into an aromatic extract stream and a nonaromatic raffinate stream.

Abstract: A crystalline zeolite SSZ-32 of novel composition is prepared using an N-lower alkyl-N'-isopropyl-imidazolium cation as a template. Also disclosed is a process for converting hydrocarbons with crystalline zeolite SSZ-32.

Abstract: Zeolite L with flat basal planes, and reduced crystallite size is prepared in a synthesis modified by the addition of small amounts of additional metal such as magnesium, calcium, barium, cobalt, zinc, chromium, manganese or nickel. The addition of these metals also suppresses unwanted zeolite W formation even when the synthesis would otherwise form this zeolite.

Abstract: A reforming process, selective for the dehydrocyclization of paraffins to aromatics, is effected using a bed of catalyst particles containing multiple Group VIII (8-10) noble metals having different gradients within the catalyst particles and a nonacidic large-pore molecular sieve. The use of this bed of catalyst particles results in greater selectivity of conversion of paraffins to aromatics and improved catalyst stability, particularly in the presence of small amounts of sulfur.

Abstract: A naphtha feed is contacted in a penultimate aromatic forming stage under catalytic aromatic forming conditions with a first catalyst. The effluent from the penultimate stage is contacted in a final aromatic forming stage under catalytic aromatic forming conditions and at substantially the same pressure as is maintained in the penultimate stage with a second catalyst. The pressure is selected to provide optimal aromatic production per calendar day from the final stage.

Abstract: A method for preparing a dialkylnaphthalene in one step by contacting an dialkylbenzene compound with a solid catalyst in a gas or liquid phase in the presence of hydrogen, using a catalyst having composition (I) or (II) below:(1)(M.sup.1).sub.a.(M.sup.2).sub.b.(SiO.sub.2.XAl.sub.2 O.sub.3).(Al.sub.2 O.sub.3).sub.c (I)(2) Mixture of II-(i) and II-(ii):(M.sup.3).sub.d.(Al.sub.2 O.sub.3) II-(i)(M.sup.4).sub.e.(SiO.sub.2.XAl.sub.2 O.sub.3) II-(ii)wherein M.sup.1 is a metal selected from the group consisting of metals belonging to group VIII of a periodic table and rhenium;M.sup.2 is a member selected from the group consisting of zinc, gallium, and oxides thereof;M.sup.3 is a metal belonging to group VIII of a periodic table;M.sup.4 is at least one alkali metal; anda, b, c, d, e, and X represent proportions, respectively.

Abstract: A process for producing aromatic hydrocarbons comprising contacting at least one hydrocarbon of the paraffin series, olefin series, acetylene series, cyclic paraffin series or cyclic olefin series with a catalyst containing an L-type zeolite containing both platinum components and halogen components supported thereon, the catalyst having a peak intensity of 0.4 or less as determined by X-ray absorption near edge structure (XANES), and the amount of dealuminization in the zeolite is 3% by weight or less, based on the total amount of aluminum therein.

Abstract: Reforming and dehydrocyclization catalysts and processes are disclosed wherein reforming catalysts comprise a Group VIII metal and at least one bound medium pore non-zeolitic molecular sieve characterized in the calcined form by an adsorption of isobutane of at least 2 percent by weight at a partial pressure of 500 torr and a temperature of 20.degree. C. and characterized by an adsorption of triethylamine less than about 5 percent by weight at a partial pressure of 2.6 torr and a temperature of 22.degree. C. The binder preferably is alumina and/or silica, and the Group VIII metal preferably is platinum.

Abstract: A process for efficiently producing 2,6-dimethylnaphthalene which comprises subjecting 2-methyl-1-(p-tolyl)butene and/or 2-methyl-1-(p-tolyl)butane as the starting raw material to a cyclization dehydrogenation reaction in the presence of a catalyst comprising (a) a palladium component, (b) an alkali or alkaline earth metal compound and (c) aluminum oxide. The process enables the production of highly pure 2,6-dimethylnaphthalene in a high yield at a low cost. The catalyst used in the process affords high safety and stability.

Abstract: Zeolite L containing caesium is prepared by a process in which said zeolite L is crystallised from a synthesis mixture with a molar composition (expressed as oxides) of:______________________________________ K.sub.2 O/SiO.sub.2 0.15 to 0.40 K.sub.2 O/Cs.sub.2 O 3 to 10 H.sub.2 O/K.sub.2 O 40 to 100 and SiO.sub.2 /Al.sub.2 O.sub.3 7 to 13 ______________________________________and containing 0.5 to 15 ppm (by weight) of divalent metal carbons, e.g. Mg ions. The zeolite L is used in dehydrocyclisation and/or isomerisation processes.

Abstract: A process for preparing aromatic compounds, wherein a gaseous feed containing C.sub.6 to C.sub.20 hydrocarbons is reacted in the presence of a catalyst, which catalyst comprises as its catalytically active component a hydrotalcite-type material having in its uncalcined state the general formulaMe'(II).sub.z Me(II).sub.x Me(III).sub.y (CO.sub.3)(OH).sub.2(x+z)+3y-2.aqwith an X-ray diffraction (d003) greater than about 7.4 Angstroms, and whereinMe'(II) is at least one divalent metal selected from the Group comprising platinum, palladium, silver, ruthenium and iridium;ME(II) is at least one divalent metal selected from the Group comprising copper, cobalt, magnesium, manganese, nickel and zinc;ME(III) is at least one trivalent metal selected from the Group comprising aluminum, chromium and iron; andx, y and z are positive numbers satisfying the following relationships:(x+z)/y.gtoreq.0.5;0<z/y.ltoreq. 3; andx.gtoreq.0.

Abstract: For the catalytic aromatization of hydrocarbons containing 5 to 9 carbons atoms per molecule, use is made of a catalyst containing a MFI zeolite containing at least one noble metal from the platinum family and at least one additional metal chosen from the group constituted by tin, germanium, lead and indium, and optionally an amorphous matrix.

Abstract: A catalytic dehydrogenation and/or dehydrocyclization of paraffins.

Abstract: Rare earth oxides, such as Nd.sub.2 O.sub.3 disperse onto the surface of SiO.sub.2 /Al.sub.2 O.sub.3 and act as weakly basic titrants. This lowers the acidity of SiO.sub.2 /Al.sub.2 O.sub.3 to close to that of chlorided alumina, as shown by model compound reaction tests. This support also disperses a noble metal such as Pt much better than undoped SiO.sub.2 /Al.sub.2 O.sub.3 and similar to chlorided alumina. Platinum on the rare earth modified silica alumina can function as a hydrocarbon conversion catalyst in reactions where Pt/chlorided Al.sub.2 O.sub.3 is used, such as in reforming, and isomerization, especially wax isomerization.

Abstract: A process for preparing aromatic compounds, wherein a gaseous feed containing C.sub.6 to C.sub.20 hydrocarbons is reacted in the presence of a catalyst, which catalyst comprises a metal from Group VIII of the Periodic Table loaded on a hydrotalcite-type support material having in its uncalcined state the general formulaMe(II).sub.x Me(III).sub.y (CO.sub.3)(OH).sub.2x+3y-2 . aqwith an x-ray diffraction (d003) greater than about 7.4 Angstroms, and whereinMe(II) is at least one divalent metal selected from the group comprising copper, magnesium, manganese, zinc and a metal from Group VIII of the Periodic Table;Me(III) is at least one trivalent metal selected from the group comprising aluminum, chromium and iron; andx and y are positive numbers satisfying the following relationship x/y.gtoreq.0.5.

Abstract: A contact material composition of an intimately mixed halogencontaining mixed oxide of at least one cationic species of a naturally occurring Group IIIB element, at least one cationic species of a Group IIA metal of magnesium, calcium, strontium and barium and at least one cationic species of germanium and gallium, as well as methods for hydrocarbon conversion using such contact material compositions are provided.

Abstract: The present invention provides a method and apparatus for reforming a hydrocarbon feedstock in the presence of steam using a steam-active reforming catalyst The present invention can generally be used in conjunction with any steam-active reforming processes wherein the hydrocarbon reforming and catalyst regeneration operations are conducted simultaneously and the catalyst is regenerated using a steam-diluted oxygen (or air) regeneration medium. In the present invention, catalyst regeneration effluent gas is advantageously reused in the reforming operation to provide at least a portion of the steam environment required for reforming the hydrocarbon feedstock. Free oxygen is preferably removed from the regeneration effluent gas before the regeneration effluent gas is brought into contact with the hydrocarbon feedstock.

Abstract: For the aromatization of hydrocarbons containing 2 to 4 carbon atoms per molecule in the presence of a specific and preferably acid catalyst, the catalyst contains an MFI zeolite in which is introduced at least one noble metal from the platinum family and at least one additional metal chosen from within the group consisting of tin, germanium, lead and indium, and the catalyst optionally contains an amorphous matrix.

Abstract: Reforming and dehydrocyclization catalysts and processes are disclosed wherein reforming catalysts comprise a Group VIII metal and at least one medium pore non-zeolitic molecular sieve characterized in the calcined form by an adsorption of isobutane of at least 2 percent by weight at a partial pressure of 500 torr and a temperature of 20.degree. C. and characterized by an adsorption of triethylamine less than about 5 percent by weight at a partial pressure of 2.6 torr and a temperature of 22.degree. C. In one embodiment the catalyst includes a Group VII metal on a halogenated carrier.

Abstract: The catalyst is an L-type zeolite with platinum supported thereon, which is then treated with a halogen-containing compound. The catalyst has a long catalyst life and is extremely useful for the preparation of aromatic hydrocarbons from aliphatic hydrocarbons. The process using the catalyst provides a production of aromatic hydrocarbons with a high yield.

Abstract: A high aromatic-content solvent having a boiling point range of 185.degree.-245.degree. C. and a mixed aniline point of not higher than 21.degree. C. is produced by reforming a petroleum fraction containing at least 50% by volume of components having a boiling point range of 150.degree.-215.degree. C. and then subjecting to a fractional distillation.

Abstract: A Pt/Ba/USY catalyst prepared with a high SiO.sub.2 /Al.sub.2 O.sub.3 ratio USY gives improved aromatics selectivity compared to other Pt/USY containing catalysts. The improved selectivity is a result of the method of catalyst preparation which includes incorporation of a Group IIA metal after platinum incorporation.

Abstract: The preferred reforming and/or benzene production catalyst is an intermediate pore size zeolite which has a high degree of crystallinity and a small crystallite size. The reforming or benzene production process using the catalyst is preferably run without added hydrogen, and at low pressures and temperatures.

Abstract: A catalytic process for converting low molecular weight non-aromatic compounds into higher molecular weight aromatic compounds utilizes a unique zeolite catalyst with improved hydrocarbon conversion. The catalyst is a crystalline aluminosilicate having a SiO.sub.2 /Al.sub.2 O.sub.3 ratio greater than 5 and preferably a MFI or MEL zeolite. The zeolite contains a Group VIIIA metal, preferably nickel, and is subjected to thermal or hydrothermal treatments under controlled conditions of temperature, time or steam partial pressure so as to effect a decrease in the amount of carbon deposited as the zeolite catalyst. The catalyst can be used in a process for the conversion of light hydrocarbon feedstocks to improve aromatization activity.

Abstract: The present invention is a process for regenerating a large-pore zeolitic catalyst that has been deactivated by the formation of Group VIII metal agglomerates on the catalyst surface. In the process, the Group VIII metal agglomerates are redispersed to produce agglomerates of small size. It comprises an oxychlorination step, a nitrogen purge step and a reduction step.

Abstract: A process for producing monosubstituted monoalkylaromatics from C.sub.8 +n-paraffins-containing feeds, by contacting the feeds with a non-acid catalyst comprising a microporous crystalline material containing tin, indium, thallium or lead, is disclosed.

Abstract: A deactivated catalyst comprising a nonacidic zeolite and a Group VIII metal is regenerated by a two-step carbon burn process. The first oxidation step contacts the nonacidic zeolite catalyst with a halogen-free gaseous stream comprising oxygen and an inert gas at a first temperature sufficient to combust carbonaceous material while maintaining a substantial portion of the active Group VIII metal surface area withn the micropores of the nonacidic zeolite for a first period of time sufficient to substantially complete combustion of at least a portion the carbonaceous material at the first temperature. The second step contacts this nonacidic zeolite catalyst with a gaseous stream comprising oxygen and an inert gas at a second temperature sufficient to combust any remaining carbonaceous material for a second period of time sufficient to maintain a substantial portion of the active Group VIII metal surface area in the micropores of the nonacidic zeolite catalyst.