# US 11,439,986 B2 · Silver impregnation solution containing high-boiling oxygenated additive and its use in ethylene oxide catalyst preparation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,439,986 B2 - Document ID: US11439986B2 - Status: Granted - Kind: B2 - Application number: 15/839,987 - Filed: 2017-12-13 - Published: 2019-06-13 - Granted: 2022-09-13 - Earliest claimed: 2017-12-13 - Assignees: Scientific Design Company, Inc. - Applicants: Scientific Design Company, Inc. - Inventors: Evgeny Beletskiy - Web page: https://patentgrep.com/patent/US11439986B2 ## CPC - B01J 23/50: Silver - B01J 37/0203: {the impregnation liquid containing organic compounds} - B01J 37/0213: {Preparation of the impregnating solution} - B01J 37/08: Heat treatment {(B01J37/0009, B01J37/0018 take precedence)} - C07D 301/02: Synthesis of the oxirane ring - B01J 2235/00: Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties - B01J 2235/30: Scanning electron microscopy; Transmission electron microscopy - Y02P 20/52: using catalysts, e.g. selective catalysts - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A silver impregnation solution containing: (i) silver ions, (ii) a polar organic additive containing two to four carbon atoms and two to four functional groups selected from hydroxy, carboxylic acid, and amine groups, provided that a carboxylic acid group can only be present along with a hydroxy or amine group, and provided that an amine group can only be present along with a hydroxy or carboxylic acid group; and (iii) water; wherein components (i) and (ii) are water soluble and dissolved in the impregnation solution. Also described herein is a method for producing a catalyst effective in the oxidative conversion of ethylene to ethylene oxide, the method comprising subjecting a refractory carrier impregnated with the above-described silver impregnation solution to a calcination process. Also described herein is a method for converting ethylene to ethylene oxide by use of the foregoing silver catalyst, as produced by the above-described silver impregnation solution. ## Claims ### Claim 1 A silver impregnation solution comprising: (i) silver ions, (ii) a polar organic additive containing two to four carbon atoms and at least one hydroxy group and at least one carboxylic acid group; and (iii) water; wherein components (i) and (ii) are water soluble and dissolved in said impregnation solution; wherein said polar organic additive is present in said silver impregnation solution in an amount of 0.1-5 wt %; and wherein the silver impregnation solution excludes a main group promoting species. ### Claim 2 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive has a boiling point of 100-400° C. ### Claim 3 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive has a boiling point of 150-400° C. ### Claim 4 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive is present in said silver impregnation solution in an amount of 1-5 wt %. ### Claim 5 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive is present in said silver impregnation solution in an amount of 0.5-3 wt %. ### Claim 6 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive is present in said silver impregnation solution in an amount of 1-3 wt %. ### Claim 7 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive is selected from glycolic acid, lactic acid, 3-hydroxypropionic acid, 4-hydroxybutyric acid, and 3-hydroxybutyric acid. ### Claim 8 (depends on 1) The silver impregnation solution of claim 1, wherein said silver impregnation solution further comprises (iv) at least one organic amine. ### Claim 9 (depends on 8) The silver impregnation solution of claim 8, wherein said organic amine is ethylene diamine. ### Claim 10 (depends on 1) The silver impregnation solution of claim 1, wherein said silver impregnation solution further comprises a catalyst promoting species selected from alkali, alkaline earth, and transition metals. ### Claim 11 (depends on 1) The silver impregnation solution of claim 1, wherein said silver impregnation solution further comprises rhenium as a catalyst promoting species. ### Claim 12 (depends on 1) The silver impregnation solution of claim 1, wherein said silver impregnation solution further comprises cesium as a catalyst promoting species. ### Claim 13 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive contains two to four carbon atoms, one hydroxy group, and one carboxylic acid group. ### Claim 14 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive is glycolic acid. ### Claim 15 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive is present in said silver impregnation solution in an amount of 0.1-1.8 wt %. ### Claim 16 (depends on 1) The silver impregnation solution of claim 1, wherein said polar organic additive is present in said silver impregnation solution in an amount of 0.1-1.5 wt %. ### Claim 17 A silver impregnation solution consisting of: (i) silver ions, (ii) a polar organic additive containing two to four carbon atoms and at least one hydroxy group and at least one carboxylic acid group; (iii) water; (iv) optionally, at least one organic amine; and (v) optionally, a promoting species; wherein components (i) and (ii) are water soluble and dissolved in said impregnation solution; wherein said polar organic additive is present in said silver impregnation solution in an amount of 0.1-5 wt %. ### Claim 18 A method for producing a catalyst effective in the oxidative conversion of ethylene to ethylene oxide, the method comprising subjecting a refractory carrier impregnated with a silver impregnation solution to a calcination process, wherein said silver impregnation solution comprises: (i) silver ions, (ii) a polar organic additive containing two to four carbon atoms and at least one hydroxy group and at least one carboxylic acid group; and (iii) water; wherein components (i) and (ii) are water soluble and dissolved in said impregnation solution; and wherein said polar organic additive is present in said silver impregnation solution in an amount of 0.1-5 wt %; and wherein the silver impregnation solution excludes a main group promoting species. ### Claim 19 (depends on 18) The method of claim 18, wherein the refractory carrier comprises alumina. ### Claim 20 (depends on 18) The method of claim 18, wherein the refractory carrier is impregnated with the silver impregnation solution by immersing the refractory carrier into the silver impregnation solution. ### Claim 21 (depends on 18) The method of claim 18, wherein said polar organic additive has a boiling point of 100-400° C. ### Claim 22 (depends on 18) The method of claim 18, wherein said polar organic additive has a boiling point of 150-400° C. ### Claim 23 (depends on 18) The method of claim 18, wherein said polar organic additive is present in said silver impregnation solution in an amount of 1-5 wt %. ### Claim 24 (depends on 18) The method of claim 18, wherein said polar organic additive is present in said silver impregnation solution in an amount of 0.5-3 wt %. ### Claim 25 (depends on 18) The method of claim 18, wherein said polar organic additive is present in said silver impregnation solution in an amount of 1-3 wt %. ### Claim 26 (depends on 18) The method of claim 18, wherein said polar organic additive is selected from glycolic acid, lactic acid, 3-hydroxypropionic acid, 4-hydroxybutyric acid, and 3-hydroxybutyric acid. ### Claim 27 (depends on 18) The method of claim 18, wherein said silver impregnation solution further comprises (iv) at least one organic amine. ### Claim 28 (depends on 27) The method of claim 27, wherein said organic amine is ethylene diamine. ### Claim 29 (depends on 18) The method of claim 18, wherein said silver impregnation solution further comprises a catalyst promoting species selected from alkali, alkaline earth, and transition metals. ### Claim 30 (depends on 18) The method of claim 18, wherein said silver impregnation solution further comprises rhenium as a catalyst promoting species. ### Claim 31 (depends on 18) The method of claim 18, wherein said silver impregnation solution further comprises cesium as a catalyst promoting species. ### Claim 32 (depends on 18) The method of claim 18, wherein said catalyst, as produced after said calcination process, is exposed to an atmosphere having a humidity level of at least 80% for at least six hours. ### Claim 33 (depends on 18) The method of claim 18, wherein said catalyst, as produced after said calcination process, is exposed to an atmosphere having a humidity level of at least 90% for at least six hours.