Abstract: A carrier for an ethylene epoxidation catalyst, the carrier comprising a porous alumina body formed of sintered particles of alumina in a substantial absence of inorganic binder species other than alumina, wherein the substantial absence of inorganic binder species corresponds to an amount of less than 0.6 wt % inorganic binder species other than alumina and comprises at least a substantial absence of silicon-containing species.

Abstract: A method for producing a catalyst effective in the oxidative conversion of ethylene to ethylene oxide, the method comprising: (i) impregnating a porous refractory carrier with a sub-catalytic level of silver ion in a range of 0.1 wt % to 1 wt % of silver by weight of the carrier and silver, and at least partially reducing said silver ion to elemental silver to produce a low-silver catalyst precursor having isolated silver atoms or silver nanoparticles on surfaces of said refractory carrier; and (ii) further impregnating the low-silver catalyst precursor with a catalytic amount of silver ion of at least 10 wt % total amount of silver and at least one promoting species by weight of the carrier and silver, and subjecting the further impregnated carrier to an elevated temperature of at least 200° C. to completely reduce silver ion to elemental silver in the carrier. The low-silver catalyst precursor produced in step (i) is also described in detail.

Abstract: A carrier for an ethylene epoxidation catalyst, the carrier comprising a porous alumina body formed of sintered particles of alumina in a substantial absence of inorganic binder species other than alumina, wherein the substantial absence of inorganic binder species corresponds to an amount of less than 0.6 wt % inorganic binder species other than alumina and comprises at least a substantial absence of silicon-containing species.

Abstract: The present disclosure is directed to the preparation of silver-based HSCs. During preparation of the catalyst a selected carrier is co-impregnated with a solution containing a catalytically effective amount of silver and a promoting amount of rhenium and other promoters. After co-impregnation, the carrier is subjected to a separate heat treatment prior to calcination. Such heat treatment is conducted for between about 1 minute and about 120 minutes at temperatures between about 40° C. and about 300° C. Catalysts prepared by the present methodology evidence improved selectivity, activity and/or stability resulting in an increase in the useful life of the catalyst.

Abstract: A method for producing a catalyst effective in the oxidative conversion of ethylene to ethylene oxide, the method comprising: (i) impregnating a porous refractory carrier with a sub-catalytic level of silver ion in a range of 0.1 wt % to 1 wt % of silver by weight of the carrier and silver, and at least partially reducing said silver ion to elemental silver to produce a low-silver catalyst precursor having isolated silver atoms or silver nanoparticles on surfaces of said refractory carrier; and (ii) further impregnating the low-silver catalyst precursor with a catalytic amount of silver ion of at least 10 wt % total amount of silver and at least one promoting species by weight of the carrier and silver, and subjecting the further impregnated carrier to an elevated temperature of at least 200° C. to completely reduce silver ion to elemental silver in the carrier. The low-silver catalyst precursor produced in step (i) is also described in detail.

Abstract: A carrier for an ethylene epoxidation catalyst, the carrier comprising a porous alumina body formed of sintered particles of alumina in a substantial absence of inorganic binder species other than alumina, wherein the substantial absence of inorganic binder species corresponds to an amount of less than 0.6 wt % inorganic binder species other than alumina and comprises at least a substantial absence of silicon-containing species.

Abstract: A high selectivity catalyst start-up process is provided in which an excess level of chloride moderator (greater than 1 ppm) is present in the feed gas composition during each of the various stages of the start-up process. The excess level of chloride used in the start-up process maintains a low level of selectivity (less than 86%) during the entire start-up process. Despite the low selectivity values achieved during the start-up process of the present disclosure, high selectivity catalysts that are conditioned by such a start-up process exhibit improved catalyst performance during the normal operation of the catalyst.

Abstract: 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 liquid silver-containing solution to a calcination process, wherein the calcination process comprises a solvent removal step in which the silver-impregnated carrier is heated to a base temperature (Tbase) of at least 80° C. and up to about 200° C. to produce a dry carrier impregnated with ionic silver, followed by a silver reduction step in which the dry carrier is gradually heated above the base temperature to a maximum temperature (Tmax) of at least 350° C. and up to about 500° C. and then gradually cooled to the base temperature, wherein the method is conducted such that (Tbase?Tmax)×HW is at least 2000 min.° C. wherein HW is a full width at half maximum of a temperature versus time curve delineated by the silver reduction step.

Abstract: The present invention relates to an improved carrier for an ethylene epoxidation catalyst, the carrier comprising alumina in combination with a stability-enhancing amount of mullite. The invention is also directed to an improved catalyst containing the improved carrier, as well as an improved process for the epoxidation of ethylene using the catalyst of the invention.

Abstract: An improved carrier for an ethylene epoxidation catalyst is provided. The carrier includes an alumina component containing a first portion of alumina particles having a mean primary particle size of, or greater than, 2 ?m and up to 6 ?m, and a second portion of alumina particles having a particle size less than 2 ?m. An improved catalyst containing the above-described carrier, as well as an improved process for the epoxidation of ethylene using the catalyst are also provided.

Abstract: A high selectivity catalyst start-up process is provided in which an excess level of chloride moderator (greater than 1 ppm) is present in the feed gas composition during each of the various stages of the start-up process. The excess level of chloride used in the start-up process maintains a low level of selectivity (less than 86%) during the entire start-up process. Despite the low selectivity values achieved during the start-up process of the present disclosure, high selectivity catalysts that are conditioned by such a start-up process exhibit improved catalyst performance during the normal operation of the catalyst.

Abstract: 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 liquid silver-containing solution to a calcination process, wherein the calcination process comprises a solvent removal step in which the silver-impregnated carrier is heated to a base temperature (Tbase) of at least 80° C. and up to about 200° C. to produce a dry carrier impregnated with ionic silver, followed by a silver reduction step in which the dry carrier is gradually heated above the base temperature to a maximum temperature (Tmax) of at least 350° C. and up to about 500° C. and then gradually cooled to the base temperature, wherein the method is conducted such that (Tbase?Tmax)×HW is at least 2000 min.° C. wherein HW is a full width at half maximum of a temperature versus time curve delineated by the silver reduction step.

Abstract: An improved carrier for an ethylene epoxidation catalyst is provided. The carrier includes an alumina component containing a first portion of alumina particles having a particle size of, or greater than, 3 ?m and up to 6 ?m, and a second portion of alumina particles having a particle size of, or less than, 2 ?m. An improved catalyst containing the above-described carrier, as well as an improved process for the epoxidation of ethylene using the catalyst are also provided.

Abstract: The present invention relates to an improved carrier for an ethylene epoxidation catalyst, the carrier comprising alumina in combination with a stability-enhancing amount of mullite. The invention is also directed to an improved catalyst containing the improved carrier, as well as an improved process for the epoxidation of ethylene using the catalyst of the invention.

Abstract: The present invention relates to an improved carrier for an ethylene epoxidation catalyst, the carrier comprising alumina in combination with a stability-enhancing amount of mullite. The invention is also directed to an improved catalyst containing the improved carrier, as well as an improved process for the epoxidation of ethylene using the catalyst of the invention.

Abstract: An improved carrier for an ethylene epoxidation catalyst is provided. The carrier includes an alumina component containing a first portion of alumina particles having a mean primary particle size of, or greater than, 2 ?m and up to 6 ?m, and a second portion of alumina particles having a particle size less than 2 ?m. An improved catalyst containing the above-described carrier, as well as an improved process for the epoxidation of ethylene using the catalyst are also provided.

Abstract: An improved carrier for an ethylene epoxidation catalyst is provided. The carrier includes an alumina component containing a first portion of alumina particles having a particle size of, or greater than, 3 ?m and up to 6 ?m, and a second portion of alumina particles having a particle size of, or less than, 2 ?m. An improved catalyst containing the above-described carrier, as well as an improved process for the epoxidation of ethylene using the catalyst are also provided.

Abstract: A geometrically shaped solid carrier is provided that improves the performance and effectiveness of an olefin epoxidation catalyst for epoxidizing an olefin to an olefin oxide. In particular, improved performance and effectiveness of an olefin epoxidation catalyst is achieved by utilizing a geometrically shaped refractory solid carrier in which at least one wall thickness of said carrier is less than 2.5 mm.

Abstract: This invention relates to an improved process for preparing silver catalysts useful for the vapor phase production of ethylene oxide from ethylene and oxygen. An inert support is impregnated with a solution of a catalytically effective amount of a silver containing compound, a promoting amount of an alkali metal containing compound, and a promoting amount of a transition metal containing compound. The impregnated support is calcined by heating at a temperature of from about 200° C. to about 600° C. to convert the silver in the silver containing compound to metallic silver and to decompose and remove substantially all organic materials. The heating is conducted under an atmosphere comprising a combination of an inert gas and from about 10 ppm to about 5% by volume of a gas of an oxygen containing oxidizing component.

Abstract: A carrier for a catalyst useful for the epoxidation of an olefin which comprises an inert, refractory solid carrier is provided. The carrier has no or little absolute volume from small pores, of less than 1 micrometer, and large pores, of above 5 micrometer. By “no or little absolute volume from small pores of less than 1 micron” it is meant that the pore volume of such pores is less than 0.20 ml/g. By “no or little absolute volume from large pores of above 5 micron” it is meant that the pore volume of such pores is less than 0.20 ml/g. The invention further provides a catalyst useful for the epoxidation of an olefin supported on such a carrier and a process for the oxidation of an olefin, especially ethylene, to an olefin oxide, especially ethylene oxide.