United States Patent (19) 11 Patent Number: 4,880,764 Imai et al. (45) Date of Patent: "k Nov. 14, 1989 54 DEHYDROGENATION CATALYST AND 3,931,054 1/1976 Lester .................................. 502/332 PROCESS 3,936,395 2/1976 Hayes ....... ... 252/466 4,003,852 1/1977 Hayes ....... ... 252/466 (75) Inventors: Tamotsu Imai, Mt. Prospect; Hayim 4,104,317 8/1978 Antos ....... ... 585/434 Abrevaya, Wilmette, both of Ill, Y 4,672,146 6/1987 Abrevaya. ... 585/660 4,716, 143 12/1987 Inai .......... ... 585/660 73 Assignee: UOP, Des Plaines, Ill. 4,786,625 1/1988 Imai et al. ... 585/660 Notice: The portion of the term of this patent 4,827,072 5/1989 Imai .......... ... 585/443 subsequent to Nov. 22, 2005 has been Primary Examiner-Asok Pal disclaimed. 57 ABSTRACT Appl. No.: 21 289,137 A novel catalytic composite and a process of its use is 22 Fied: Dec. 23, 1988 disclosed. The catalyst comprises a platinum group metal component, a first modifier component selected Related U.S. Application Data from Group IA and IIA elements of the Periodic Table, 60 Continuation-in-part of Ser. No. 221,977, Jul. 20, 1988, a second modifier components selected from the group Pat. No. 4,827,072, which is a division of Ser. No. of elements consisting of palladium, iridum, and os 31,882, Dec. 11, 1987, Pat. No. 4,786,625, which is a mium, and a third modifier component selected from continuation-in-part of Ser. No. 18,541, Feb. 25, 1987, the elements of Group IVA of the Peridoic Table of the Pat. No. 4,716,143, which is a continuation-in-part of Elements. All of the catalytic components are located Ser. No. 871,356, Jun. 6, 1986, abandoned. on a refractory oxide support having a nominal diame (51) Int. Cl." ....................... B01J 21/04; B01J 23/58; ter (d) of from 50 to 1000 microns. The catalytic com BOJ 23/62 posite is characterized in that the second modifier com (52) U.S. C. .................................... 502/326; 502/327; ponent is surface-impregnated upon the support in such 502/328; 502/330; 502/349; 502/352; 502/514; a manner that the average concentration of the surface 502/523: 502/527; 585/660 impregnated second modifier component on the outside (58 Field of Search ............... 585/443, 444, 445, 460; 0.2d micron catalyst layer is at least 2 times the average 502/326, 328, 327, 330, 349,352, 514,523, 527 concentration of the second modifier component in 0.4d 56 References Cited micron diameter cehter core of the catalyst where d is U.S. PATENT DOCUMENTS the nominal diameter, and wherein the first modifier metal component is uniformly impregnated. The cata 3,259,589 7/1966 Michalko ............................ 502/334 3,367,888 2/1968 Hoekstra ............................. 502/334 lytic composite has been found to be most useful in the 3,651,167 3/1972 De Rosset ........................... 585/260 dehydrogenation of dehydrogenatable hydrocarbons. 3,755,481 8/1973 Hayes .................................. 585/434 3,761,531 9/1973 Bloch .................................. 585/434 11 Claims, 2 Drawing Sheets U.S. Patent Nov. 14, 1989 Sheet 1 of 2 4,880,764 ||O 008OOZ009OOÇOOpº009:OO?OO/O 00|-----|------| -|-O 0,7 /º//,6-y ———————\!\, 4,880,764 1. 2 reduction step prior to its use in the conversion of hy DEHYDROGENATION CATALYST AND PROCESS drocarbons. It is further disclosed that the step is de signed to ensure a uniform and finely divided dispersion CROSS-REFERENCE TO RELATED of metallic components throughout the carrier material. APPLICATIONS 5 Related U.S. Pat. Nos. 3,682,838 and 3,761,531 dis This application is a continuation-in-part of prior close catalytic composites comprising a platinum group copending application Ser. No. 221,977 filed July 20, component, and a Group IVA metallic component. As 1988 now U.S. Pat. No. 4,827,072, which in turn is a with the previous references it is disclosed therein that Rule 1.60 Division of application Ser. No. 131,882 filed it is preferred that the catalysts are subjected to a reduc Dec. 11, 1987, now U.S. Pat. No. 4,786,625 which is a 9 tion step prior to their use. It is further disclosed in these continuation-in-part of application Ser. No. 018,541 references that the reduction step is designed to assure filed Feb. 25, 1987, now U.S. Pat. No. 4,716,143, which uniform distribution of the metallic particles throughout is a continuation-in-part of application Ser. No. 871,356 the catalysts. filed June 6, 1986, now abandoned. U.S. Pat. Nos. 3,558,477, 3,562,147, 3,584,060, and 15 3,649,566 all disclose catalytic composites comprising a BACKGROUND OF THE INVENTION platinum group component, and a rhenium component This invention relates to the conversion of hydrocar on a refractory oxide support. However, as before these bons, especially the dehydrogenation of dehydrogena references disclose that the best results ae achieved table hydrocarbons, in the presence of a catalyst com when the platinum group component and rhenium com posite. This invention also pertains to a new catalyst 20 ponent are uniformly distributed throughout the surface composite. and pores of the catalyst. The dehydrogenation of hydrocarbons is an impor tant commercial process because of the great demand U.S. Pat. No. 3,897,368 describes a method for the for dehydrogenated hydrocarbons for the manufacture production of a noble metal containing catalyst where of various chemical products such as detergents, high 25 the noble metal is platinum and the platinum is the only octane gasolines, pharmaceutical products, plastics, catalytic metal present and it is deposited selectively synthetic rubbers, and other products well known to upon the external surface of the catalyst. This disclosure those skilled in the art. One example of this process is describes a method of producing a catalyst containing dehydrogenating isobutane to produce isobutylene platinum only by impregnating platinum on the exterior which can be polymerized to provide tackifying agents 30 layer of the particle. The method claimed utilizes a for adhesives, viscosity-index additives for motor oils non-ionic surface active agent to achieve the surface and impact-resistant and anti-oxidant additives for plas impregnation of the noble metal. Additionally, U.S. Pat. tics. Nos. 3,367,888; 3,931,054; and 3,259,589 all teach meth ods of impregnating a catalyst with a Group VIII metal INFORMATION DISCLOSURE 35 component that is similar to the method employed to Several catalytic composites relevant to the composi produce the surface-impregnated catalyst of the instant tion of the instant invention are disclosed in the art, invention. However, the '054 patent describes a method however, no references or combination of references of impregnating a catalyst base such that the Group discloses the unique combination of components of the VIII metal component is located below the surface of catalyst of this invention. U.S. Pat. Nos. 3,936,395 and 40 the catalyst. In addition, the 368, '888, and '589 patents 4,003,852 both disclose a catalytic composition contain describe a method of making a catalyst where said cata ing platinum or palladium, iridium, an alkali or alkaline lyst does not contain the useful modifier metal compo earth metal, and a fourth component. The fourth com nents of the instant invention. Thus, while these disclo ponent of the '852 patent may be tin or lead while the sures describe a portion of the method used to fabricate fourth component of the 395 patent is germanium. In 45 the catalyst of the instant invention, they do not teach both of these patents, it is specifically disclosed and the entire method as described herein. Surprisingly, it claimed that all components are uniformly impregnated has been discovered that by surface impregnating upon upon the non-acidic catalytic composite. These patents the catalyst support substantially all of the platinum are distinguished from the catalyst of the instant inven group metal component and uniformly impregnating tion in that the iridium component of the instant catalyst 50 the other catalytic effective components, a catalyst is surface-impregnated on the catalyst support. displaying improved performance in a dehydrogenation Numerous catalytic composites comprising a group process is obtained. VIII metal component and a modifier metal component selected from the group consisting of a tin component, SUMMARY OF THE INVENTION germanium component, rhenium component, and mix- 55 It is an object of the present invention to provide an tures thereof are known. For example related U.S. Pat. improved catalytic composite. A corollary objective is Nos. 3,632,503, 3,755,481, and 3,878,131 disclose cata to provide an improved process for the conversion of lysts comprising a platinum group component, a tin hydrocarbons and especially for the dehydrogenation component, and a germanium component on a porous of dehydrogenatable hydrocarbons using the improved carrier material. However, these references disclose 60 catalytic composite. that best results are achieved when a germanium com Accordingly, in a broad embodiment, the present ponent is uniformly distributed throughout the carrier invention is a catalytic composite comprising a platinum material. However, the reference is silent as to any component, a first catalytic modifier component se advantage to be achieved by limiting the location of lected from Group IA and IIA elements of the Periodic substantially all of the catalytic metals to an outer layer 65 Table of the Elements or mixtures thereof, a second of the catalyst particle. In fact, it is indicated in these catalytic modifier component selected from the group references that it is preferred that the catalytic compos iridium, osmium, or mixtures thereof, and a third cata ite thereof be subjected to a substantially water-free lytic modifier component selected from the elements of 4,880,764 3 4.