Catalysts having enhanced stability, efficiency and/or activity for alkylene oxide production

Abstract

A catalyst for the manufacture of alkylene oxide, for example ethylene oxide, by the vapor-phase epoxidation of alkene containing impregnated silver and at least one efficiency-enhancing promoter on an inert, refractory solid support, said support incorporating a sufficient amount of zirconium component (present and remaining substantially as zirconium silicate) as to enhance at least one of catalyst activity, efficiency and stability as compared to a similar catalyst which does not contain the zirconium component.

1 . A catalyst for the manufacture of alkylene oxide by the vapor-phase epoxidation of alkene, said catalyst comprising impregnated silver and at least one efficiency-enhancing promoter on a refractory solid support, said support incorporating a sufficient amount of zirconium component to enhance at least one of catalyst activity, efficiency and stability as compared to a similar catalyst which does not contain the zirconium component, said zirconium component being present in the support substantially as zirconium silicate.  
   
   
       2 . (canceled)  
   
   
       3 . (canceled)  
   
   
       4 . The catalyst of  claim 1  wherein the impregnated silver is present from about 2 to 60% by weight of the catalyst.  
   
   
       5 . The catalyst of  claim 4  wherein the impregnated silver is present from about 5 to 50% by weight of the catalyst.  
   
   
       6 . The catalyst of  claim 5  wherein the impregnated silver is present from about 10 to 40% by weight of the catalyst.  
   
   
       7 . The catalyst of  claim 1  wherein at least one of the efficiency enhancing promoters comprises at least one alkali metal, alkaline earth metal and/or oxyanion of an element, other than oxygen, having an atomic number of 5 to 83 and being selected from groups 3b through 7b and 3a through 7a of the Periodic Table.  
   
   
       8 . The catalyst of  claim 1  wherein at least one of the efficiency-enhancing promoters is a member of a redox-half reaction pair.  
   
   
       9 . The catalyst of  claim 7  wherein at least one of the efficiency-enhancing promoters is a rhenium component.  
   
   
       10 . The catalyst of  claim 1  wherein the refractory solid support, exclusive of zirconium component, is at least 95% by weight alpha alumina.  
   
   
       11 . The catalyst of  claim 10  wherein the refractory solid support, exclusive of zirconium component, contains less than about 2000 ppmw calcium.  
   
   
       12 . The catalyst of  claim 11  wherein the refractory solid support, exclusive of zirconium component, contains less than about 350 ppmw calcium.  
   
   
       13 . The catalyst of  claim 10  wherein the refractory solid support, exclusive of zirconium component and calcium compounds, contains less than about 500 ppmw alkaline earth metal, measured as the alkaline earth metal oxide.  
   
   
       14 . The catalyst of  claim 1  wherein the refractory solid support, exclusive of zirconium component, is at least 99% by weight alpha alumina.  
   
   
       15 . The catalyst of  claim 14  wherein the refractory solid support, exclusive of zirconium component, contains less than about 2000 ppmw calcium.  
   
   
       16 . The catalyst of  claim 15  wherein the refractory solid support exclusive of zirconium component contains less than about 350 ppmw calcium.  
   
   
       17 . The catalyst of  claim 14  wherein the refractory solid support, exclusive of zirconium component and calcium compounds, contains less than about 500 ppmw alkaline earth metal, measured as the alkaline earth metal oxide.  
   
   
       18 . The catalyst of  claim 14  wherein the refractory solid support has a morphology comprising interlocking platelets of alpha-alumina.  
   
   
       19 . The catalyst of  claim 1  wherein the said refractory solid support has a surface area of at least about 0.5 m2/g, a pore volume of at least about 0.5 cc/g, and a median pore diameter between about 1 to 50 microns.  
   
   
       20 . The catalyst of  claim 1  wherein the zirconium component comprises from about 0.01 to 10.0% by weight of zirconium silicate based on the total weight of the support.  
   
   
       21 . The catalyst of  claim 20  wherein the zirconium component comprises from about 0.1 to 5.0% by weight of zirconium silicate based on the total weight of the support.  
   
   
       22 . The catalyst of  claim 21  wherein the zirconium component comprises from about 0.3 to 3.0% by weight of zirconium silicate based on the total weight of the support.  
   
   
       23 . A method for the epoxidation of an alkene comprising the steps of: contacting a feed comprising an alkene and oxygen with the catalyst of  claim 1 .  
   
   
       24 . The method of  claim 23  wherein said alkylene oxide is ethylene oxide.  
   
   
       25 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component deposited on a fluoride-mineralized carrier; and producing a product mix comprising an olefin oxide, wherein the partial pressure of olefin oxide in the product mix is greater than about 60 kPa.  
   
   
       26 . A process as claimed in  claim 25 , wherein the catalyst additionally comprises a high-selectivity dopant.  
   
   
       27 . A process as claimed in  claim 26 , wherein the high-selectivity dopant comprises a rhenium component.  
   
   
       28 . A process as claimed in  claim 25 , wherein the catalyst additionally comprises Group IA metal component.  
   
   
       29 . A process as claimed in  claim 25 , wherein the carrier comprises alpha-alumina.  
   
   
       30 . A process as claimed in  claim 25 , wherein the olefin comprises ethylene.  
   
   
       31 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component and a high-selectivity dopant deposited on a fluoride-mineralized carrier; and producing a product mix comprising an olefin oxide, wherein the partial pressure of olefin oxide in the product mix is greater than about 20 kPa.  
   
   
       32 . A process as claimed in  claim 31 , wherein the high-selectivity dopant comprises a rhenium component.  
   
   
       33 . A process as claimed in  claim 32 , wherein the catalyst additionally comprises a rhenium co-promoter.  
   
   
       34 . A process as claimed in  claim 31 , wherein the catalyst additionally comprises a Group IA metal component.  
   
   
       35 . A process as claimed in  claim 31 , wherein the process employs a fixed bed, tubular reactor.  
   
   
       36 . A process as claimed in  claim 31 , wherein the partial pressure of olefin oxide is greater than about 30 kPa.  
   
   
       37 . A process as claimed in  claim 31 , wherein the partial pressure of olefin oxide is from about 40 kPa to about 60 kPa.  
   
   
       38 . A process as claimed in  claim 31 , wherein the carrier comprises alpha-alumina.  
   
   
       39 . A process as claimed in  claim 31 , wherein the olefin comprises ethylene.  
   
   
       40 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component deposited on a carrier having a particulate matrix having a lamellar or platelet-type morphology; and producing a product mix comprising an olefin oxide, wherein the partial pressure of olefin oxide in the product mix is greater than about 60 kPa.  
   
   
       41 . A process as claimed in  claim 40 , wherein the lamellar or platelet-type morphology is such that particles having in at least one direction a size greater than 0.1 micrometer have at least one substantially flat major surface.  
   
   
       42 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component and a high-selectivity dopant deposited on a carrier having a particulate matrix having a lamellar or platelet-type morphology; and producing a product mix comprising an olefin oxide, wherein the partial pressure of olefin oxide in the product mix is greater than about 20 kPa.  
   
   
       43 . A process as claimed in  claim 42 , wherein the high selectivity dopant comprises a rhenium component and the catalyst additionally comprises a rhenium co-promoter.  
   
   
       44 . A process as claimed in  claim 42 , wherein the lamellar or platelet-type morphology is such that particles having in at least one direction a size greater than 0.1 micrometer have at least one substantially flat major surface.  
   
   
       45 . A process for the production of a 1,2-diol, a 1,2-diol ether or an alkanolamine comprising converting an olefin oxide into the 1,2-diol, the 1,2-diol ether or the alkanolamine wherein the olefin oxide has been obtained by a process for the epoxidation of an olefin as claimed in  claim 25 .  
   
   
       46 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component deposited on an alpha-alumina carrier; and producing a product mix comprising an olefin oxide, wherein the partial pressure of olefin oxide in the product mix is from about 20 to 28 kPa, and wherein said alpha-alumina is prepared by a process comprising the step of contacting an alpha-alumina precursor with fluoride anions.  
   
   
       47 . A process as claimed in  claim 46 , wherein said alpha-alumina is prepared by contacting an alpha-alumina precursor with fluoride anions followed by calcining the fluoride-contacted alpha-alumina precursor under conditions sufficient to form platelets of alpha-alumina.  
   
   
       48 . A process as claimed in  claim 46 , wherein the catalyst additionally comprises a promoter selected from the group consisting of compounds of rhenium, molybdenum, tungsten, and an efficiency-enhancing salt of a member of a redox half-reaction pair comprising nitrate, nitrite, or other anions capable of forming nitrate anions under epoxidation conditions in the presence of a nitrogen-containing gaseous efficiency-enhancing member of a redox half-reaction pair.  
   
   
       49 . A process as claimed in  claim 48 , wherein the promoter comprises a rhenium component.  
   
   
       50 . A process as claimed in  claim 46 , wherein the catalyst additionally comprises a Group IA metal cation.  
   
   
       51 . A process as claimed in  claim 46 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof;    b) peptizing the alumina of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    c) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    d) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    e) calcining the dried formed alumina of step (d).    
   
   
       52 . A process as claimed in  claim 51 , wherein zirconium silicate is mixed with the alumina of step (a) prior to the peptizing step.  
   
   
       53 . A process as claimed in  claim 46 , wherein the olefin comprises ethylene.  
   
   
       54 . A process as claimed in  claim 49 , wherein the catalyst additionally comprises a rhenium co-promoter.  
   
   
       55 . A process as claimed in  claim 48 , wherein the process employs a fixed bed, tubular reactor.  
   
   
       56 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component deposited on an alpha-alumina carrier comprising particles each of which has at least one substantially major surface having a lamellate or platelet morphology; and producing a product mix comprising an olefin oxide, wherein the partial pressure of olefin oxide in the product mix is from about 20 to 28 kPa.  
   
   
       57 . A process as claimed in  claim 56 , wherein said alpha-alumina is prepared by contacting an alpha-alumina precursor with fluoride anions followed by calcining the fluoride-contacted alpha-alumina precursor under conditions sufficient to form platelets of alpha-alumina.  
   
   
       58 . A process as claimed in  claim 56 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof;    b) peptizing the alumina of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    c) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    d) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    e) calcining the dried formed alumina of step (d).    
   
   
       59 . A process as claimed in  claim 58 , wherein zirconium silicate is mixed with the alpha-alumina precursor of step (a) prior to the peptizing step.  
   
   
       60 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component and a promoter selected from the group consisting of compounds of rhenium, molybdenum, tungsten, and an efficiency-enhancing salt of a member of a redox half-reaction pair comprising nitrate, nitrite, or other anions capable of forming nitrate anions under epoxidation conditions in the presence of a nitrogen-containing gaseous efficiency-enhancing member of a redox half-reaction pair deposited on an alpha-alumina carrier comprising particles each of which has at least one substantially major surface having a lamellate or platelet morphology; and producing a product mix comprising an olefin oxide, wherein the partial pressure of olefin oxide in the product mix is from about 20 to 28 kPa.  
   
   
       61 . A process as claimed in  claim 60 , wherein said alpha-alumina is prepared by contacting an alpha-alumina precursor with fluoride anions followed by calcining the fluoride-contacted alpha-alumina precursor under conditions sufficient to form platelets of alpha-alumina.  
   
   
       62 . A process as claimed in  claim 60 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof;    b) peptizing the alumina of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    c) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    d) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    e) calcining the dried formed alumina of step (d).    
   
   
       63 . A process as claimed in  claim 62 , wherein zirconium silicate is mixed with the alpha-alumina precursor of step (a) prior to the peptizing step (b).  
   
   
       64 . A process as claimed in  claim 60 , wherein the catalyst additionally comprises a rhenium component and the catalyst additionally comprises a rhenium co-promoter.  
   
   
       65 . A process as claimed in  claim 64 , wherein said rhenium co-promoter is selected from the group consisting of compounds of tungsten, molybdenum, sulfur and mixtures thereof.  
   
   
       66 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component and a high-selectivity dopant deposited on a fluoride-mineralized carrier; and producing a product mix comprising an olefin oxide, wherein the concentration of carbon dioxide in the feed is less than about 2 mole-%, relative to the total feed.  
   
   
       67 . A process as claimed in  claim 66 , wherein the concentration of carbon dioxide in the feed is less that about 1 mole-%, relative to the total feed.  
   
   
       68 . A process as claimed in  claim 66 , wherein the concentration of carbon dioxide in the feed is less that about 0.75 mole-%, relative to the total feed.  
   
   
       69 . A process as claimed in  claim 66 , wherein the concentration of carbon dioxide in the feed is at least 0.1 mole-%, relative to the total feed.  
   
   
       70 . A process as claimed in  claim 66 , wherein the concentration of carbon dioxide in the feed is at least 0.3 mole-%, relative to the total feed.  
   
   
       71 . A process as claimed in  claim 66 , wherein the concentration of carbon dioxide in the feed is between about 0.50 mole-% and 0.75 mole-%, relative to the total feed.  
   
   
       72 . A process as claimed in  claim 66 , wherein the high-selectivity dopant comprises a rhenium component.  
   
   
       73 . A process as claimed in  claim 72 , wherein the catalyst additionally comprises a rhenium co-promoter.  
   
   
       74 . A process as claimed in  claim 66 , wherein the process employs a fixed bed, tubular reactor.  
   
   
       75 . A process as claimed in  claim 66 , wherein the carrier comprises alpha-alumina.  
   
   
       76 . A process as claimed in  claim 66 , wherein the olefin comprises ethylene.  
   
   
       77 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component and a rhenium component deposited on a fluoride-mineralized carrier; and producing a product mix comprising an olefin oxide, wherein the concentration of carbon dioxide in the feed is less than about 2 mole-%, relative to the total feed.  
   
   
       78 . A process as claimed in  claim 77 , wherein the concentration of carbon dioxide in the feed is less that about 1 mole-%, relative to the total feed.  
   
   
       79 . A process as claimed in  claim 77 , wherein the concentration of carbon dioxide in the feed is less that about 0.75 mole-%, relative to the total feed.  
   
   
       80 . A process as claimed in  claim 77 , wherein the concentration of carbon dioxide in the feed is at least 0.1 mole-%, relative to the total feed.  
   
   
       81 . A process as claimed in  claim 77 , wherein the concentration of carbon dioxide in the feed is at least 0.3 mole-%, relative to the total feed.  
   
   
       82 . A process as claimed in  claim 77 , wherein the concentration of carbon dioxide in the feed is between about 0.50 mole-% and 0.75 mole-%, relative to the total feed.  
   
   
       83 . A process as claimed in  claim 77 , wherein the catalyst additionally comprises a rhenium co-promoter.  
   
   
       84 . A process as claimed in  claim 77 , wherein the catalyst additionally comprises a Group IA metal component.  
   
   
       85 . A process as claimed in  claim 77 , wherein the carrier comprises alpha-alumina.  
   
   
       86 . A process as claimed in  claim 77 , wherein the olefin comprises ethylene.  
   
   
       87 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component and a high-selectivity dopant deposited on a carrier having a particulate matrix having a lamellar or platelet-type morphology; and producing a product mix comprising an olefin oxide, wherein the concentration of carbon dioxide in the feed is less than about 2 mole-%, relative to the total feed.  
   
   
       88 . A process as claimed in  claim 87 , wherein the lamellar or platelet-type morphology is such that particles having in at least one direction a size greater than 0.1 micrometer have at least one substantially flat major surface.  
   
   
       89 . A process for the production of a 1,2-diol, a 1,2-diol ether or an alkanolamine comprising converting an olefin oxide into the 1,2-diol, the 1,2-diol ether or the alkanolamine wherein the olefin oxide has been obtained by a process for the epoxidation of an olefin as claimed in  claim 65 .  
   
   
       90 . A process for the epoxidation of an olefin comprising the steps of: feeding a gas mixture comprising an olefin and oxygen to a reactor containing a catalyst comprising a silver component and a promoter selected from the group consisting of compounds of rhenium, molybdenum, tungsten, and an efficiency-enhancing salt of a member of a redox half-reaction pair comprising nitrate, nitrite, or other anions capable of forming nitrate anions under epoxidation conditions in the presence of a nitrogen-containing gaseous efficiency-enhancing member of a redox half-reaction pair deposited on an alpha-alumina carrier; and producing a product mix comprising an olefin oxide, wherein the concentration of carbon dioxide in the gas mixture contacting the catalyst is about 0.5 mole-% or less, and wherein said alpha-alumina is prepared by a process comprising the step of contacting an alpha-alumina precursor with fluoride anions.  
   
   
       91 . A process as claimed in  claim 90 , wherein said alpha-alumina is prepared by contacting an alpha-alumina precursor with fluoride anions followed by calcining the fluoride-contacted alpha-alumina precursor under conditions sufficient to form platelets of alpha-alumina.  
   
   
       92 . A process as claimed in  claim 90 , wherein the concentration of carbon dioxide in the feed to the reactor is 0.0 mole-%, relative to the total feed to the reactor.  
   
   
       93 . A process as claimed in  claim 92 , wherein said process takes place in a back-mixed autoclave with internal gas recycle.  
   
   
       94 . A process as claimed in  claim 93 , wherein the concentration of carbon dioxide in the gas mixture contacting the catalyst is about 0.4 mole-%.  
   
   
       95 . A process as claimed in  claim 90 , wherein the promoter comprises a rhenium component.  
   
   
       96 . A process as claimed in  claim 95 , wherein the catalyst additionally comprises a rhenium co-promoter.  
   
   
       97 . A process as claimed in  claim 90 , wherein the catalyst additionally comprises an alkali metal component.  
   
   
       98 . A process as claimed in  claim 90 , wherein the process employs a fixed bed, tubular reactor.  
   
   
       99 . A process as claimed in  claim 90 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 (a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof;    (b) peptizing the alumina of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    (c) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    (d) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    (e) calcining the dried formed alumina of step (d).    
   
   
       100 . A process as claimed in  claim 90 , wherein the olefin comprises ethylene.  
   
   
       101 . A process for the epoxidation of an olefin comprising the steps of: feeding a gas mixture comprising an olefin and oxygen to a reactor containing a catalyst comprising a silver component and a rhenium component deposited on an alpha-alumina carrier; and producing a product mix comprising an olefin oxide, wherein the concentration of carbon dioxide in the gas mixture contacting the catalyst is about 0.5 mole-% or less, and wherein said alpha-alumina is prepared by a process comprising the step of contacting an alpha-alumina precursor with fluoride anions.  
   
   
       102 . A process as claimed in  claim 101 , wherein said alpha-alumina is prepared by contacting an alpha-alumina precursor with fluoride anions followed by calcining the fluoride-contacted alpha-alumina precursor under conditions sufficient to form platelets of alpha-alumina.  
   
   
       103 . A process as claimed in  claim 101 , wherein the concentration of carbon dioxide in the feed to the reactor is 0.0 mole-%, relative to the total feed to the reactor.  
   
   
       104 . A process as claimed in  claim 103 , wherein said process takes place in a back-mixed autoclave with internal gas recycle.  
   
   
       105 . A process as claimed in  claim 104 , wherein the concentration of carbon dioxide in the gas mixture contacting the catalyst is about 0.4 mole-%.  
   
   
       106 . A process as claimed in  claim 103 , wherein the catalyst additionally comprises a rhenium co-promoter selected from the group consisting of tungsten, molybdenum, sulfur and mixtures thereof.  
   
   
       107 . A process as claimed in  claim 101 , wherein the catalyst additionally comprises an alkali metal component.  
   
   
       108 . A process as claimed in  claim 101 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof;    b) peptizing the alumina of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    c) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    d) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    e) calcining the dried formed alumina of step (d).    
   
   
       109 . A process as claimed in  claim 101 , wherein the olefin comprises ethylene.  
   
   
       110 . A process for the epoxidation of an olefin comprising the steps of: feeding a gas mixture comprising an olefin and oxygen to a reactor containing a catalyst comprising a silver component and a promoter selected from the group consisting of compounds of rhenium, molybdenum, tungsten, and an efficiency-enhancing salt of a member of a half-reaction pair comprising nitrate, nitrite, or other anions capable of forming nitrate anions under epoxidation conditions in the presence of a nitrogen-containing gaseous efficiency-enhancing member of a redox half-reaction pair deposited on an alpha-alumina carrier comprising particles each of which has at least one substantially major surface having a lamellate or platelet morphology; and producing a product mix comprising an olefin oxide, wherein the concentration of carbon dioxide in the gas mixture contacting the catalyst is about 0.5 mole-% or less.  
   
   
       111 . A process as claimed in  claim 1   10 , wherein said alpha-alumina is prepared by contacting an alpha-alumina precursor with fluoride anions followed by calcining the fluoride-contacted alpha-alumina precursor under conditions sufficient to form platelets of alpha-alumina.  
   
   
       112 . A process as claimed in  claim 11   0 , wherein the concentration of carbon dioxide in the feed to the reactor is 0.0 mole-%, relative to the total feed to the reactor.  
   
   
       113 . A process as claimed in  claim 112 , wherein said process takes place in a back-mixed autoclave with internal gas recycle.  
   
   
       114 . A process as claimed in  claim 113 , wherein the concentration of carbon dioxide in the gas mixture contacting the catalyst is about 0.4 mole-%.  
   
   
       115 . A process as claimed in  claim 11   0 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof;    b) peptizing the alumina of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    c) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    d) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    e) calcining the dried formed alumina of step (d).    
   
   
       116 . A process as claimed in  claim 115 , wherein zirconium silicate is mixed with the alpha-alumina precursor of step (a) prior to the peptizing step (b).  
   
   
       117 . A process for preparing a fluoride-mineralized carrier which process comprises incorporating into the carrier at any stage of the carrier preparation a strength-enhancing additive.  
   
   
       118 . A process as claimed in  claim 117 , wherein the strength-enhancing additive is selected from the group consisting of a zirconium species, a lanthanide Group species, a Group II metal species, an inorganic glass, and mixtures thereof.  
   
   
       119 . A process as claimed in  claim 118 , wherein the strength-enhancing additive comprises calcium.  
   
   
       120 . A process as claimed in  claim 118 , wherein the strength-enhancing additive comprises cerium.  
   
   
       121 . A process for preparing a carrier having a particulate matrix having a lamellar or platelet-type morphology which process comprises incorporating into the carrier at any stage of the carrier preparation a strength-enhancing additive.  
   
   
       122 . A process as claimed in  claim 121 , wherein the strength-enhancing additive is selected from the group consisting of a zirconium species, a lanthanide Group species, a Group II metal species, an inorganic glass, and mixtures thereof.  
   
   
       123 . A fluoride-mineralized carrier having incorporated therein a strength-enhancing additive.  
   
   
       124 . A fluoride-mineralized carrier as claimed in  claim 123 , wherein the strength-enhancing additive is selected from the group consisting of a zirconium species, a lanthanide Group species, a Group II metal species, an inorganic glass, and mixtures thereof.  
   
   
       125 . A fluoride-mineralized carrier as claimed in  claim 124 , wherein the strength-enhancing additive comprises calcium.  
   
   
       126 . A fluoride-mineralized carrier as claimed in  claim 124 , wherein the strength-enhancing additive comprises cerium.  
   
   
       127 . A fluoride-mineralized carrier as claimed in  claim 123 , wherein the carrier comprises alpha-alumina.  
   
   
       128 . A carrier having a particulate matrix having a lamellar or platelet-type morphology having incorporated therein a strength-enhancing additive.  
   
   
       129 . A carrier as claimed in  claim 128 , wherein the strength-enhancing additive is selected from the group consisting of a zirconium species, a lanthanide Group species, a Group II metal species, an inorganic glass, and mixtures thereof.  
   
   
       130 . A catalyst comprising a catalytic species deposited on a fluoride-mineralized carrier, wherein the fluoride-mineralized carrier has incorporated therein a strength-enhancing additive.  
   
   
       131 . A catalyst as claimed in  claim 130 , wherein the catalytic species comprises one or more of silver, molybdenum, nickel, and tungsten.  
   
   
       132 . A catalyst as claimed in  claim 131 , wherein the catalytic species comprises silver.  
   
   
       133 . A catalyst as claimed in  claim 130 , wherein the strength-enhancing additive is selected from the group consisting of a zirconium species, a lanthanide Group species, a Group II metal species, an inorganic glass, and mixtures thereof.  
   
   
       134 . A catalyst as claimed in  claim 133  wherein the strength-enhancing additive comprises calcium.  
   
   
       135 . A catalyst as claimed in  claim 133 , wherein the strength-enhancing additive comprises cerium.  
   
   
       136 . A catalyst as claimed in  claim 130 , wherein the carrier comprises alpha-alumina.  
   
   
       137 . A catalyst comprising a silver component deposited on a fluoride-mineralized carrier, wherein the fluoride-mineralized carrier has incorporated therein a strength-enhancing additive.  
   
   
       138 . A catalyst as claimed in  claim 137 , wherein the strength-enhancing additive is selected from the group consisting of a zirconium species, a lanthanide Group species, a Group II metal species, an inorganic glass, and mixtures thereof.  
   
   
       139 . A catalyst as claimed in  claim 137 , wherein the catalyst additionally comprises a high selectivity dopant.  
   
   
       140 . A catalyst as claimed in  claim 137 , wherein the catalyst additionally comprises a Group IA metal component.  
   
   
       141 . A catalyst as claimed in  claim 137 , wherein the catalyst additionally comprises a rhenium component, or a rhenium component and a rhenium co-promoter.  
   
   
       142 . A catalyst comprising a catalytic species deposited on a carrier having a particulate matrix having a lamellar or platelet-type morphology, wherein the carrier has incorporated therein a strength-enhancing additive.  
   
   
       143 . A catalyst as claimed in  claim 142 , wherein the strength-enhancing additive is selected from the group consisting of a zirconium species, a lanthanide Group species, a Group II metal species, an inorganic glass, and mixtures thereof.  
   
   
       144 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component deposited on a fluoride-mineralized carrier; and producing a product mix comprising an olefin oxide, wherein the fluoride-mineralized carrier has incorporated therein a strength-enhancing additive.  
   
   
       145 . A process as claimed in  claim 144  wherein the strength-enhancing additive is selected from the group consisting of a zirconium species, a lanthanide Group species, a Group II metal species, an inorganic glass, and mixtures thereof.  
   
   
       146 . A process as claimed in  claim 144 , wherein the catalyst additionally comprises a rhenium component, or a rhenium component and a rhenium co-promoter and wherein the concentration of carbon dioxide in the feed is less that about 1 mole-%.  
   
   
       147 . A process as claimed in  claim 146 , wherein the concentration of carbon dioxide in the feed is between about 0.50 mole-% and 0.75 mole-%.  
   
   
       148 . A process as claimed in  claim 144 , wherein the olefin comprises ethylene.  
   
   
       149 . A process for the epoxidation of an olefin comprising the steps of: contacting a feed comprising an olefin and oxygen with a catalyst comprising a silver component deposited on a carrier having a particulate matrix having a lamellar or platelet-type morphology; and producing a product mix comprising an olefin oxide, wherein the carrier has incorporated therein a strength-enhancing additive.  
   
   
       150 . A process as claimed in  claim 149 , wherein the strength-enhancing additive is selected from the group consisting of a zirconium species, a lanthanide Group species, a Group II metal species, an inorganic glass, and mixtures thereof.  
   
   
       151 . A process for the production of a 1,2-diol, a 1,2-diol ether or an alkanolamine comprising converting an olefin oxide into the 1,2-diol, the 1,2-diol ether or the alkanolamine wherein the olefin oxide has been obtained by a process for the epoxidation of an olefin as claimed in  claim 144 .  
   
   
       152 . A process for preparing a carrier comprising alpha-alumina which process comprises incorporating as an additive into the carrier a zirconium component, wherein said alpha-alumina is prepared by a process comprising the step of contacting an alpha-alumina precursor with fluoride anions and wherein said zirconium component is present in the carrier substantially as zirconium silicate.  
   
   
       153 . A process as claimed in  claim 152 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 (a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof to form an alumina precursor;    (b) peptizing the alumina precursor mixture of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    (c) mixing zirconium silicate with one or more of the alumina precursor of step (a) and the peptized fluorinated alumina of step (b);    (d) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    (e) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    (f) calcining the dried formed alumina of step (d);    wherein the formed alumina of steps (d), (e) and (f) comprises a mixture with zirconium silicate.    
   
   
       154 . A process for preparing an alpha-alumina carrier comprising particles each of which has at least one substantially major surface having a lamellate or platelet morphology which process comprises incorporating as an additive into the carrier a zirconium component wherein said zirconium component is present in the carrier substantially as zirconium silicate.  
   
   
       155 . A process as claimed in  claim 154 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 (a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof to form an alumina precursor;    (b) peptizing the alumina precursor mixture of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    (c) mixing zirconium silicate with one or more of the alumina precursor of step (a) and the peptized fluorinated alumina of step (b);    (d) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    (e) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    (f) calcining the dried formed alumina of step (d);    wherein the formed alumina of steps (d), (e) and (f) comprises a mixture with zirconium silicate.    
   
   
       156 . An alpha-alumina carrier having incorporated therein as an additive a zirconium component, wherein said alpha-alumina is prepared by a process comprising the step of contacting an alpha-alumina precursor with fluoride anions, and wherein said zirconium component is present in the carrier substantially as zirconium silicate.  
   
   
       157 . An alpha-alumina carrier comprising particles each of which has at least one substantially major surface having a lamellate or platelet morphology, said carrier having incorporated therein as an additive a zirconium component, wherein said zirconium component is present in the carrier substantially as zirconium silicate.  
   
   
       158 . A carrier as claimed in  claim 157 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 (a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof to form an alumina precursor;    (b) peptizing the alumina precursor mixture of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    (c) mixing zirconium silicate with one or more of the alumina precursor of step (a) and the peptized fluorinated alumina of step (b);    (d) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    (e) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    (f) calcining the dried formed alumina of step (d);    wherein the formed alumina of steps (d), (e) and (f) comprises a mixture with zirconium silicate.    
   
   
       159 . A catalyst comprising a catalytic species deposited on an alpha-alumina carrier having incorporated therein as an additive a zirconium component, wherein said alpha-alumina is prepared by a process comprising the step of contacting an alpha-alumina precursor with fluoride anions and wherein said zirconium component is present in the carrier substantially as zirconium silicate.  
   
   
       160 . A catalyst as claimed in  claim 159 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 (a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof to form an alumina precursor;    (b) peptizing the alumina precursor mixture of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    (c) mixing zirconium silicate with one or more of the alumina precursor of step (a) and the peptized fluorinated alumina of step (b);    (d) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    (e) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    (f) calcining the dried formed alumina of step (d);    wherein the formed alumina of steps (d), (e) and (f) comprises a mixture with zirconium silicate.    
   
   
       161 . A catalyst comprising a silver component deposited on an alpha-alumina carrier having incorporated therein as an additive a zirconium component, wherein said alpha-alumina is prepared by a process comprising the step of contacting an alpha-alumina precursor with fluoride anions and wherein said zirconium component is present in the carrier substantially as zirconium silicate.  
   
   
       162 . A catalyst as claimed in  claim 161 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 (a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof to form an alumina precursor;    (b) peptizing the alumina precursor mixture of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    (c) mixing zirconium silicate with one or more of the alumina precursor of step (a) and the peptized fluorinated alumina of step (b);    (d) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    (e) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    (f) calcining the dried formed alumina of step (d);    wherein the formed alumina of steps (d), (e) and (f) comprises a mixture with zirconium silicate.    
   
   
       163 . A catalyst as claimed in  claim 161 , wherein the catalyst additionally comprises a promoter selected from the group consisting of compounds of rhenium, molybdenum, tungsten and an efficiency-enhancing salt of a member of a redox half-reaction pair comprising nitrate, nitrite, or other anions capable of forming nitrate anions under epoxidation conditions in the presence of a nitrogen-containing gaseous efficiency-enhancing member of a redox half-reaction pair.  
   
   
       164 . A catalyst as claimed in  claim 161 , wherein the catalyst additionally comprises a Group IA metal cation.  
   
   
       165 . A catalyst as claimed in  claim 161 , wherein the catalyst additionally comprises a rhenium component, or a rhenium component and a rhenium co-promoter.  
   
   
       166 . A catalyst comprising a catalytic species deposited on an alpha-alumina carrier comprising particles each of which has at least one substantially major surface having a lamellate or platelet morphology, said carrier having incorporated therein as an additive a zirconium component, and wherein said zirconium component is present in the carrier substantially as zirconium silicate.  
   
   
       167 . A catalyst as claimed in  claim 166 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 (a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof to form an alumina precursor;    (b) peptizing the alumina precursor mixture of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    (c) mixing zirconium silicate with one or more of the alumina precursor of step (a) and the peptized fluorinated alumina of step (b);    (d) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    (e) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    (f) calcining the dried formed alumina of step (d);    wherein the formed alumina of steps (d), (e) and (f) comprises a mixture with zirconium silicate.    
   
   
       168 . A process for the epoxidation of an olefin comprising the steps of: feeding a gas mixture comprising an olefin and oxygen to a reactor containing a catalyst comprising a silver component deposited on an alpha-alumina carrier; and producing a product mix comprising an olefin oxide, wherein the alpha-alumina carrier has incorporated therein as an additive a zirconium component and wherein said alpha-alumina is prepared by a process comprising the step of contacting an alpha-alumina precursor with fluoride anions and wherein said zirconium component is present in the carrier substantially as zirconium silicate.  
   
   
       169 . A process as claimed in  claim 168 , wherein the catalyst additionally comprises a rhenium component, or a rhenium component and a rhenium co-promoter.  
   
   
       170 . A process as claimed in  claim 169 , wherein the concentration of carbon dioxide in the feed to the reactor is 0.0 mole-%.  
   
   
       171 . A process as claimed in  claim 169 , wherein the concentration of carbon dioxide in the gas mixture contacting the catalyst is from about 0.4 to 0.5 mole %.  
   
   
       172 . A process as claimed in  claim 169 , wherein the concentration of carbon dioxide in the gas mixture contacting the catalyst is about 0.5 mole %.  
   
   
       173 . A process as claimed in  claim 170 , wherein said process takes place in a back mixed autoclave with internal gas recycle.  
   
   
       174 . A process as claimed in  claim 168 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 (a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof to form an alumina precursor;    (b) peptizing the alumina precursor mixture of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    (c) mixing zirconium silicate with one or more of the alumina precursor of step (a) and the peptized fluorinated alumina of step (b);    (d) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    (e) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    (f) calcining the dried formed alumina of step (d);    wherein the formed alumina of steps (d), (e) and (f) comprises a mixture with zirconium silicate.    
   
   
       175 . A process as claimed in  claim 168 , wherein the olefin comprises ethylene.  
   
   
       176 . A process for the epoxidation of an olefin comprising the steps of: feeding a gas mixture comprising an olefin and oxygen to a reactor containing a catalyst comprising a silver component deposited on an alpha-alumina carrier comprising particles each of which has at least one substantially major surface having a lamellate or platelet morphology; and producing a product mix comprising an olefin oxide, wherein the carrier has incorporated therein as an additive a zirconium component and wherein said zirconium component is present in the carrier substantially as zirconium silicate.  
   
   
       177 . A process as claimed in  claim 176 , wherein said alpha-alumina carrier is prepared by a method comprising the steps of: 
 (a) selecting an alumina selected from the group consisting of boehmite alumina (AlOOH), gamma-alumina and mixtures thereof to form an alumina precursor;    (b) peptizing the alumina precursor mixture of step (a) with a mixture containing an acidic component and fluoride anions to provide peptized fluorinated alumina;    (c) mixing zirconium silicate with one or more of the alumina precursor of step (a) and the peptized fluorinated alumina of step (b);    (d) forming the peptized fluorinated alumina of step (b) to provide formed peptized fluorinated alumina;    (e) drying the formed peptized fluorinated alumina of step (c) to provide dried formed alumina; and    (f) calcining the dried formed alumina of step (d);    wherein the formed alumina of steps (d), (e) and (f) comprises a mixture with zirconium silicate.