Layered olefin metathesis catalyst compositions and methods of preparation and uses thereof

Abstract

Provided here are layered catalyst compositions containing a base support and an active layer containing an active metal component and an active support. The base support can be aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. The active metal component can be an oxide of one or more of chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, cobalt, nickel, ruthenium, rhodium, palladium, platinum, iridium, or osmium. The active support can be aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. Also provided here are methods of preparing the layered catalyst compositions for use in an operational metathesis reactor.

Description

LAYERED OLEFIN METATHESIS CATALYST COMPOSITIONS AND METHODS OF PREPARATION AND USES THEREOF Cross-Reference to Related Applications

[0001] This application claims priority to and the benefit of European Application No. EP24164731.2, filed on March 20, 2024. The contents of the referenced application are incorporated into the present application by reference.Technical Field

[0002] The disclosure relates to layered alumina-based catalysts, methods of their preparation, and methods for their use in metathesis reactors.Background

[0003] The need for propylene has dramatically increased in recent years in order to supply the expanding markets for acrylic acid, polypropylene, and propylene oxide. The majority of propylene generated nowadays is by either fluid catalytic cracking (FCC) units or steam cracking units, which predominantly produce ethylene. A sudden spike in the demand for propylene cannot be managed by these procedures. To change the composition of a pool of low-value butenes to satisfy the market's need for propylene, olefin metathesis would be an advantageous process. Olefin metathesis is the catalytic twofold disproportionation of the two olefin molecules' carbon double bonds through cleavage and reformation. The distribution of the overall product is constrained by thermodynamic equilibrium in this reversible reaction. Catalytic olefin metathesis transforms simple and cheap organic molecules into complex and valuable molecules. In olefin metathesis, two olefin molecules exchange the groups around the double bonds in the presence of a catalyst. The olefins can be of different compounds by structure and composition, or two identical compounds. In general, reaction temperatures for olefin metathesis reactions can be as low as atroom temperature or can be at temperatures up to about 500 °C or greater, depending on the type of feed stock, the catalyst, and the media in which the reaction is conducted. To produce propylene and other products, however, olefin metathesis catalysts frequently lack the necessary selectivity. As a result of coking from aromatic compounds, olefin metathesis catalysts can also become inactive. In industrial applications, metathesis catalysts require both high catalytic activities at low reaction temperatures and long lifetime.Summary

[0004] Applicant has identified a need for the development of highly selective and stable catalyst for metathesis reactions of butenes to propene and internal olefins. Provided here are compositions and methods to address these shortcomings of the art and provide other additional or alternative advantages. Examples of methods for preparation of layered alumina-based catalysts and methods for use of these resulting compositions in metathesis reactions are provided here.

[0005] Embodiments include layered catalyst compositions that contain an active layer and a base support. Examples of the base support can be aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. The active layer of the catalyst contains an active metal component and an active support. The active metal component can be a Group 6, 7, 8, or 9 metal oxide. The active metal component can be a chromium, molybdenum, or tungsten oxide. The active metal component can be a manganese, technetium, or rhenium oxide. The active metal component can be iron, cobalt, nickel, ruthenium, rhodium, palladium, platinum, iridium, and osmium oxide. Examples of the active metal component can be rhenium oxide or ruthenium oxide. Examples of the active support can be aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof.

[0006] An example of a layered catalyst composition contains gamma-alumina as the base support. Certain examples of the layered catalyst composition contain gamma-alumina as the base support, and the active metal component contains rhenium and the active support contains aluminum oxide. Certain examples of the layered catalyst composition contain gamma-alumina as the base support, and the active metal component contains rhenium and the active support contains zirconium oxide. In certain examples, the acidic -OH groups of the active support are increased by incorporating about 0.5 weight percent (wt.%) to 15 wt.% of an aluminum or a zirconium precursor along with the rhenium precursor. The added aluminum or zirconium precursor (active support precursor) along with the rhenium precursor produce an amorphous aluminum hydroxide or zirconium hydroxide with rhenium oxide. The amount of the metal component loaded in the active layer is reduced by at least about 10 wt.% to about 25 wt.% as compared to a rhenium oxi dealumina catalyst synthesized without aluminum / zirconium active support layer.

[0007] Certain examples of the method of producing the catalyst include mixing an aluminum precursor or a zirconium precursor with a rhenium precursor to form a highly dispersed rhenium oxide by interaction of aluminum or zirconium ions with rhenium ions during the drying and calcination process. In general, rhenium oxide loaded on the active support sinters during the regeneration process. However, due to strong interaction between the active support and the rhenium oxide, the catalyst stability can be enhanced by providing a barrier for mobility of rhenium oxide sites. Certain examples of an olefin metathesis catalyst have a base support containing aluminum oxide and an active layer containing rhenium oxide as the active metal component and aluminum oxide as the active support.

[0008] Certain examples of the method of producing the catalyst includes the following steps: degassing a y-alumina support at about 300 °C to about 600 °C under a flow of air; mixing analuminum and / or zirconium precursor with a rhenium precursor in water to form an active catalytic mixture; subjecting the y-alumina support to impregnation with the active catalytic mixture for a predetermined time period to form a layered catalyst; and drying and calcining the layered catalyst. In certain examples, the predetermined time period for impregnation ranges from about 5 minutes to about 180 minutes. The layered catalyst can be dried at temperatures between 80 °C and 230 °C. In certain examples, the layered catalyst is dried at about 160 °C. In certain examples, the layered catalyst is dried for about 6 hours to about 12 hours. The layered catalyst can be calcined at temperatures between 400 °C and 1000 °C in an oxidizing environment. In certain examples, the layered catalyst is calcined at about 550 °C under the flow of air for about 5 hours.

[0009] Certain examples of the method of producing the catalyst include the following steps: degassing a base support at about 300 °C to about 600 °C under a flow of air; mixing an active support precursor with an active metal precursor in water to form an active catalytic mixture solution; subjecting the base support to impregnation with the active catalytic mixture solution for a predetermined time period to form a metal hydroxide-impregnated wet layered catalyst; and drying and calcining the metal hydroxide-impregnated wet layered catalyst to form the layered catalyst. In certain aspects, the active metal precursor can contain an oxide of one or more of chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, cobalt, nickel, ruthenium, rhodium, palladium, or platinum, iridium, and osmium. In certain aspects, the active support precursor can be one or more of aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. In certain aspects, the base support is one or more of aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. In certain aspects, the predetermined time period for impregnation ranges from about 5minutes to about 180 minutes. In certain aspects, the impregnation is conducted at temperatures between 20 °C and 40 °C. In certain aspects, the metal hydroxide-impregnated wet layered catalyst is dried at temperatures between 80 °C and 230 °C to form a dried catalyst. In certain aspects, the metal hydroxide- impregnated wet layered catalyst is dried at about 160 °C. In certain aspects, the metal hydroxide- impregnated wet layered catalyst is dried for about 6 hours to about 12 hours. In certain aspects, the dried catalyst is calcined at temperatures between 400 °C and 1000 °C in an oxidizing environment.Brief Description of the Drawings

[0010] Examples will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements or procedures in a method. Examples are illustrated by way of example and not by way of limitation in the accompanying drawings. The present disclosure can be better understood by referring to the following figures. These drawings illustrate the principles of the disclosure and no limitation of the scope of the disclosure is thereby intended.

[0011] FIG. 1 is a diagrammatic representation of a method of preparing a layered y-alumina- based catalyst, according to an example.

[0012] FIGs. 2A and 2B are diagrammatic representations of a layered y-alumina-based catalyst as compared to a rhenium oxide-containing catalyst, according to an example.Detailed Description

[0013] The present disclosure describes various examples related to layered y-alumina-based catalyst compositions and methods of production and use in metathesis reactions. Certain examples include metathesis reactions of butenes to propene and internal olefins.

[0014] In the major industrial olefin metathesis processes using heterogeneous supported metal oxide catalysts, the heterogeneous metathesis catalysts typically contain a transition metal oxide or an organometallic complex that is fixed on a porous inorganic support. Supported metal oxide catalysts are made up of an active metal oxide component that is dispersed on an inactive oxide support. The dispersed metal oxide of the active component can be present as isolated surface species, oligomeric surface species, or clusters. These are the commonly utilized heterogeneous metathesis catalysts — MoCh / SiCh, WCh / SiCh, Re2O7 / AhO3, and (p-C4H?)4-W / SiO2. To enhance the catalytic activity, in some instances, a non-transition metallic compound is added as a promoter. Among various heterogeneous catalysts, rhenium-based metathesis catalysts are the most active and attractive in olefin metathesis because of their high potentials for practical applications. One of the advantages of rhenium catalysts is that these catalysts are more tolerant of functional groups, such as alkoxycarbonyl and alkoxy groups, than tungsten or molybdenum catalysts. Catalysts containing rhenium species are generally based on Re2O? and CH^ReOy which are deposited on AI2O3, SiO2-AhO3, TiO2, and Nt Os.

[0015] Embodiments include layered catalyst compositions that contain distinct layers, including an active layer and a base support. Examples of the base support can be one or more of aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. The active layer of the catalyst compositions contains an active metal component and an active support. In certain embodiments, the active layer of the layered catalyst contains active metal component embedded within an active support to increase catalyst stability, as shown in FIG. 1 , and discussed below. The active metal component can be a Group 6, 7, 8, or 9 metal oxide. In certain examples, the active metal component can be a chromium, molybdenum, or tungsten oxide. In certain examples, the activemetal component can be a manganese, technetium, or rhenium oxide. In certain examples, the active metal component can be iron, cobalt, nickel, ruthenium, rhodium, palladium, platinum, iridium, and osmium oxide. Examples of the active metal component can be rhenium oxide or ruthenium oxide. Examples of the active support can be one or more of aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof.

[0016] Certain examples of the method of producing the catalyst includes the following steps. The base support is subject to degassing at about 300 °C to about 600 °C under the flow of air or nitrogen. The degassed base support can be cooled in a desiccator, followed by pore volume measurement. Separately, an active support precursor is mixed with an aqueous solution of an active metal component based on pore volume of the base support. The active support precursor and the active metal component precursor are allowed to interact and impregnate on the base support for a predetermined time period to form the metal hydroxide-impregnated wet catalyst. This metal hydroxide-impregnated wet catalyst is subject to drying for a predetermined time period at temperatures between about 80 °C and about 230 °C. In certain examples, the predetermined time period for drying can range from about 6 hours to about 12 hours. In certain examples, the drying process happens in an air oven. The dried layered catalyst is then calcined for a predetermined time period at temperatures between about 400 °C to about 1000 °C to produce the layered catalyst composition. The calcination of the dried layered catalyst can be carried out in a rotary furnace. In certain examples, the dried catalyst is calcined at 550 °C under the flowing air for about 5 hours.

[0017] In the following description, reference is made to the accompanying drawings that form a part of this disclosure and numerous details are set forth in order to provide a thoroughunderstanding of the various examples. In other instances, well-known processes, devices, and systems may not been described in particular detail in order not to unnecessarily obscure the various examples. Additionally, illustrations of the various examples may omit certain features or details in order to not obscure the various examples. The drawings may provide an illustration of some of the various examples in which the subject matter of the present disclosure may be practiced. Other examples may be utilized, and logical changes may be made without departing from the scope of this disclosure.

[0018] The description may use the phrases “in some examples,” “in various examples,” “in an example,” or “in examples,” which may each refer to one or more of the same or different examples. The words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0019] The term “about” refers to a range of values including the specified value, which a person of ordinary skill in the art would consider reasonably similar to the specified value. In examples, “about” refers to values within a standard deviation using measurements generally acceptable in the art. In one non-limiting example, when the term “about” is used with a particular value, then “about” refers to a range extending to ±10% of the specified value, alternatively ±5% of the specified value, or alternatively ±1% of the specified value, or alternatively ±0.5% of the specified value. In examples, “about” refers to the specified value.

[0020] Certain examples of an olefin metathesis catalyst have a base support containing aluminum oxide and an active layer containing rhenium oxide as the active metal component and aluminum oxide as the active support.

[0021] Certain examples of the method of producing the catalyst includes the following steps. A y-alumina support is subject to degassing at about 300 °C to about 600 °C under the flow of air. The degassed y-alumina support is cooled in a desiccator, followed by pore volume measurement. Separately, an aluminum and / or zirconium precursor is mixed with a rhenium precursor in water based on pore volume of y-alumina support. The aluminum and / or zirconium precursor with the rhenium precursor is allowed to impregnate on the dried alumina support for a predetermined time period to form the active layer. In certain examples, the predetermined time period for impregnation can range from about 5 minutes to about 10 minutes. The metal hydroxide- impregnated wet catalyst is promptly subject to drying for a predetermined time period at temperatures between about 80 °C and about 230 °C to produce the layered y-alumina-based catalyst. In an example, the metal hydroxide-impregnated wet catalyst is placed on a pre-heated glass tray at about 160 °C to remove the water. In certain examples, the predetermined time period for drying can range from about 6 hours to about 12 hours. In certain examples, the drying process happens in an air oven. The layered y-alumina-based catalyst is then calcined at temperatures between about 400 °C to about 1000 °C. The calcination of the layered y-alumina-based catalyst can be carried out in a rotary furnace. In certain examples, the layered y-alumina-based catalyst is calcined at 550 °C under the flowing air for about 5 hours. In some other example, alumina and / or zirconium loading is conducted first followed by calcination by following the above steps then rhenium loading is conducted.

[0022] There are three types of surface -OH groups available on the surface of the aluminum oxide. In examples of the catalyst, the active metal ions readily occupy the basic -OH groups of the active support, then occupy the neutral -OH groups of the active support and finally the acidic -OH groups of the active support. The metathesis activity / stability of the catalyst depends mainly on the active metal ions bonded with acidic -OH sites rather than the basic and neutral -OH groups. In certain examples of the layered catalyst compositions containing rhenium, the rhenium ions readily occupy the basic -OH groups of the active support first, then occupy the neutral -OH groups of the active support and finally the acidic -OH groups of the active support. At the same time, the activity / stability of the metathesis catalyst depends mainly on the rhenium ions bonded with acidic -OH sites than the basic and neutral -OH groups. In certain examples, the acidic -OH groups of the active support are increased by incorporating about 0.5 wt.% to 15 wt.% of an aluminum and / or a zirconium precursor along with the rhenium precursor. The added aluminum and / or zirconium precursor (active support precursor) along with the rhenium precursor produce an amorphous aluminum hydroxide or zirconium hydroxide with rhenium oxide. The active layer with aluminum hydroxide or zirconium hydroxide leads to reduction of the basic and neutral -OH sites on the base support surface and leads to more acidic -OH groups available for the formation of bonds between the rhenium compounds and the active support. The amount of the metal component loaded in the active layer is reduced by at least about 10 wt.% to about 25 wt.% as compared to a rhenium oxide-alumina catalyst synthesized without aluminum and / or zirconium active support.

[0023] Certain examples of the method for producing the catalyst includes mixing an aluminum precursor or a zirconium precursor with a rhenium precursor to form a highly dispersed rhenium oxide by interaction of aluminum or zirconium ions with rhenium ions during the drying andcalcination process. In general, rhenium oxide loaded on the active support sinters during the regeneration process. However, due to strong interaction between the active support and the rhenium oxide, the catalyst stability can be enhanced by providing a barrier for mobility of rhenium oxide sites.

[0024] FIG. 1 is a diagrammatic representation of a method 100 of preparing a layered y- alumina-based catalyst, according to an example. The method 100 includes the step 102 of passing a y-alumina support precursor through an extrusion device to produce an extruded wet y-alumina support followed by drying and calcination to produce the extruded y-alumina support defining, for example, an extruded base support. This method further includes the step 104 of degassing the extruded y-alumina support at about 300 °C to about 600 °C under the flow of air, followed by cooling to produce the base y-alumina support. Separately, an aluminum and / or zirconium precursor is mixed with a rhenium precursor in water. This method further includes the step 106 of allowing the mixture of aluminum and / or zirconium precursor and the rhenium precursor solution to impregnate the base y-alumina support for a predetermined time period to produce a metal hydroxide- impregnated wet catalyst. This method further includes the step 108 of drying the metal hydroxide-impregnated wet catalyst for a predetermined time period at temperatures between about 80 °C and about 230 °C to produce the layered y-alumina-based catalyst. The drying step 108 is followed by step 110 of calcining the layered y-alumina-based catalyst at temperatures between about 400 °C to about 1000 °C. FIG. 2A is a diagrammatic representations of a layered y-alumina-based catalyst, according to an example.

[0025] A comparable example of a rhenium oxide-containing catalyst was prepared as follows. A y-alumina support is degassed at 300-600 °C under the flow of air. The degassed sample iscooled in a desiccator, followed by pore volume measurement. A rhenium precursor is dissolved in water based on pore volume of gamma alumina support. This dissolved precursor is impregnated on the dried alumina support within time frame of 5-10 mins. The metal impregnated wet catalyst was immediately transferred to a pre-heated glass tray at 160 °C to remove the water. The metal impregnated catalyst is dried at 160 °C for about 6 to 12 hours in the air oven. The dried metal impregnated catalyst is then calcined in a rotary furnace at 550 °C under the flowing air for 5 hours. FIG. 2B is a diagrammatic representations of a rhenium oxide-containing catalyst, according to a comparative example.

[0026] Certain examples of the method of producing the catalyst include the following steps: degassing a base support at about 300 °C to about 600 °C under a flow of air; mixing an active support precursor with an active metal precursor in water to form an active catalytic mixture solution; subjecting the base support to impregnation with the active catalytic mixture solution for a predetermined time period to form a metal hydroxide-impregnated wet layered catalyst; and drying and calcining the metal hydroxide-impregnated wet layered catalyst to form the layered catalyst. In certain aspects, the active metal precursor can contain an oxide of one or more of chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, cobalt, nickel, ruthenium, rhodium, palladium, or platinum, iridium, and osmium. In certain aspects, the active support precursor can be one or more of aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. In certain aspects, the base support is one or more of aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. In certain aspects, the predetermined time period for impregnation ranges from about 5 minutes to about 180 minutes. In certain aspects, the impregnation is conducted at temperaturesbetween 20 °C and 40 °C. In certain aspects, the metal hydroxide-impregnated wet layered catalyst is dried at temperatures between 80 °C and 230 °C to form a dried catalyst. In certain aspects, the metal hydroxide- impregnated wet layered catalyst is dried at about 160 °C. In certain aspects, the metal hydroxide- impregnated wet layered catalyst is dried for about 6 hours to about 12 hours. In certain aspects, the dried catalyst is calcined at temperatures between 400 °C and 1000 °C in an oxidizing environment.

[0027] Embodiments include a layered catalyst composition containing a base support and an active layer containing an active metal component and an active support. In certain aspects, the base support can be aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. In certain aspects, the active metal component can be an oxide of one or more of chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, cobalt, nickel, ruthenium, rhodium, palladium, platinum, iridium, or osmium. In certain aspects, the active support is one or more of aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof. In certain aspects, the base support is gamma-alumina and the active metal component contains rhenium and the active support contains aluminum oxide.

[0028] When ranges are disclosed herein, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, reference to values stated in ranges includes each and every value within that range, even though not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or anyother lower or upper limit, to recite a range not explicitly recited. Other objects, features and advantages of the disclosure will become apparent from the foregoing drawings, detailed description, and examples. These drawings, detailed description, and examples, while indicating specific examples of the disclosure, are given by way of illustration only and are not meant to be limiting. In further examples, features from specific examples may be combined with features from other examples. For example, features from one example may be combined with features from any of the other examples. In further examples, additional features may be added to the specific examples described herein. It should be understood that although the disclosure contains certain aspects, examples, and optional features, modification, improvement, or variation of such aspects, examples, and optional features can be resorted to by those skilled in the art, and that such modification, improvement, or variation is considered to be within the scope of this disclosure.

Claims

Claims1. A method for producing a layered catalyst, the method comprising: degassing a base support at about 300 °C to about 600 °C under a flow of air; mixing an active support precursor with an active metal precursor in water to form an active catalytic mixture solution; subjecting the base support to impregnation with the active catalytic mixture solution for a predetermined time period to form a metal hydroxide-impregnated wet layered catalyst; drying the metal hydroxide-impregnated wet layered catalyst to form a dried catalyst; and calcining the dried catalyst to form the layered catalyst.

2. The method of Claim 1, wherein the active metal precursor contains an oxide of one or more of chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, cobalt, nickel, ruthenium, rhodium, palladium, or platinum, iridium, and osmium.

3. The method of Claim 1, wherein the active support precursor is one or more of aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof.

4. The method of Claim 1, wherein the base support is aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof.

5. The method of Claim 1, wherein the predetermined time period for impregnation ranges from about 5 minutes to about 180 minutes.

6. The method of Claim 5, wherein the impregnation is conducted at temperatures between 20 °C and 40 °C.

7. The method of Claim 1, wherein the metal hydroxide-impregnated wet layered catalyst isdried at temperatures between 80 °C and 230 °C.

8. The method of Claim 7, wherein the dried catalyst is calcined at temperatures between 400 °C and 1000 °C in an oxidizing environment.

9. A layered catalyst composition comprising: an extruded base support; and an active layer calcined onto the extruded base support, the active layer containing an active metal component embedded within an active support to increase catalyst stability.

10. The layered catalyst composition of Claim 9, wherein the extruded base support is aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof.

11. The layered catalyst composition of Claim 9, wherein the active metal component is an oxide of one or more of chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, cobalt, nickel, ruthenium, rhodium, palladium, platinum, iridium, or osmium.

12. The layered catalyst composition of Claim 9, wherein the active support is one or more of aluminum oxide, gallium oxide, silica oxide, zirconium oxide, niobium oxide, titanium oxide, lanthanum oxide, cerium oxide, or combinations thereof.

13. The layered catalyst composition of Claim 9, wherein the extruded base support is gammaalumina, the active metal component contains rhenium, and the active support contains aluminum oxide.

14. The layered catalyst composition of Claim 13, wherein the active layer contains about 0.5 weight percent (wt.%) to 15 wt.% of an aluminum oxide.

15. The layered catalyst composition of Claim 9, wherein the layered catalyst is made by the method of claim 1.

Images