Claims
- 1. A process for disproportionation of aromatic compounds to a dialkyl benzene compound mixture enriched in the para-dialkylbenzene isomer, said process comprising contacting said aromatic compounds under conversion conditions with a catalyst comprising both a crystalline zeolite material having a constraint index within the approximate range of 1 to 12 and a silica/alumina mole ratio of at least 12 and a minor proportion of one or more difficultly reducible oxides, said catalyst being prepared by a method comprising contacting said catalyst with a vapor phase organophosphorus reagent selected from C.sub.1-4 alkyl phosphite esters, C.sub.1-4 alkyl phosphate esters and dimethyl-methylphosphonate, at a temperature of 100.degree. C. to 300.degree. C. and for a period of time and under conditions sufficient to either enhance para-selectivity of said catalyst or to reduce the susceptibility of said catalyst to deselectivation by contact with moisture or halogen.
- 2. A process according to claim 1 wherein said difficultly reducible oxide is selected from magnesium oxide, calcium oxide, phosphorus oxide, combinations of magnesium oxide and phosphorus oxide and combinations of calcium oxide and phosphorus oxide.
- 3. A process according to claim 1 wherein contact between catalyst and organophosphorus reagent occurs at a temperature of from about 150.degree. C. to 250.degree. C., wherein organophosphorus reagent is contacted with catalyst for a period of from about 0.2 to 1.0 hour; and wherein catalyst is contacted with at least about 0.5 gram of organophosphorus reagent per gram of catalyst per hour.
- 4. A process according to claim 1 wherein said catalyst is contacted with organophosphorus reagent admixed with an inert gaseous diluent selected from nitrogen, carbon dioxide and helium.
- 5. A process according to claim 1 wherein said zeolite is selected from ZSM-5, ZSM-11, ZSM-12, SM-23, ZSM-35, ZSM-38 and ZSM-48.
- 6. A process according to claim 1 wherein the organophosphorus reagent is trimethylphosphite, tributylphosphite, trimethylphosphate, tributylphosphate, or dimethyl-methylphosphonate.
- 7. A process according to claim 1 wherein said catalyst comprises from about 1 to 99% by weight of zeolite material with the balance of said composition comprising a binder for said zeolite material.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of copending U.S. application Ser. No. 614,195, filed May 25, 1984, now U.S. Pat. No. 4,504,690 which is a division of U.S. application Ser. No. 489,424, filed Apr. 28, 1983, now U.S. Pat. No. 4,469,806, which is a continution-in-part of U.S. application Ser. No. 359,560, filed Mar. 18, 1982, now U.S. Pat. No. 4,409,132. The entire disclosures of these applications and patents are expressly incorporated herein by reference.
US Referenced Citations (17)
Divisions (2)
|
Number |
Date |
Country |
Parent |
614195 |
May 1984 |
|
Parent |
489424 |
Apr 1983 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
359560 |
Mar 1982 |
|