Ethylene oxide catalyst and process
First Claim
1. A catalyst comprising a porous refractory support having deposited thereon a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium, and a promoting amount of Group IVB metal applied to the support in the form of oxycation-containing compound(s), wherein said Group IVB metal is selected from the group consisting of titanium, zirconium, and hafnium.
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Accused Products
Abstract
This invention relates to ethylene oxide catalyst for the vapor phase production of ethylene oxide from ethylene and oxygen prepared by impregnating a porous, refractory support having a surface area ranging from about 0.05 to about 10 m2 /g with a solubilized catalytically effective amount of silver, a solubilized promoting amount of alkali metal, a solubilized promoting amount of rhenium, and a solubilized promoting amount of hafnium metal, wherein the Group IVB metal is provided in the form of Group IVB oxycation-containing salts. The catalyst provide substantial initial activity improvement as well as long term selectivity and activity stability improvement over prior art rhenium promoted catalyst, without any loss of initial selectivity advantage.
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Citations
25 Claims
- 1. A catalyst comprising a porous refractory support having deposited thereon a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium, and a promoting amount of Group IVB metal applied to the support in the form of oxycation-containing compound(s), wherein said Group IVB metal is selected from the group consisting of titanium, zirconium, and hafnium.
- 2. A catalyst comprising a porous refractory support having deposited thereon a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium, and a promoting amount of hafnium metal applied to the support in the form of oxycation-containing compound(s).
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13. A catalyst prepared by impregnating a porous, refractory support with
(a) a solubilized catalytically effective amount of silver, (b) a solubilized promoting amount of alkali metal, (c) a solubilized promoting amount of rhenium metal, and (d) a solubilized promoting amount of hafnium metal in the form of Group IVB metal oxycation-containing compound(s).
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18. A catalyst comprising a porous refractory support comprising at least about 85 percent by weight of alpha alumina having water pore volume from about 0.3 cc/g to about 0.5 cc/g and a surface area from about 0.1 m2 /g to about 3 m2 /g having deposited thereon a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium, and a promoting amount of hafnium metal applied to the support in the form of oxycation-containing compound(s), which catalyst is prepared by impregnating said support with
(a) a solubilized catalytically effective amount of silver, (b) a solublilized promoting amount of cesium metal, (c) a solubilized promoting amount of at least one other alkali metal selected from the group consisting of lithium, sodium, potassium, and rubidium, (d) a solubilized promoting amount of rhenium, and (e) a solubilized promoting amount of hafnium oxycation-containing compound(s), sufficient to deposit on the support (i) from about 5 to about 20 percent by weight of silver compound(s) expressed as the metal based on the total weight of the catalyst, (ii) from about 0.1 micromoles to about 2 micromoles per gram of the total catalyst of hafnium, (iii) from about 50 to about 1500 ppm of cesium, expressed as the metal, (iv) from about 0.5 to about 100 micromoles of at least one other alkali metal selected from the group consisting of lithium, sodium, and potassium, expressed as the metal, per gram of total catalyst, and (v) from about 0.2 to about 5 micromoles of rhenium, expressed as the metal, per gram of the total catalyst; wherein subsequent to the impregnation step, the impregnated support is heated to reduce silver to silver metal. - View Dependent Claims (19, 20)
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21. A process for preparing a catalyst which comprises the steps of:
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(1) impregnating a porous, refractory support with (a) a solubilized catalytically effective amount of silver, (b) a solubilized promoting amount of alkali metal, (c) a solubilized promoting amount of rhenium, and (d) a solubilized promoting amount of Group IVB metal in the form of Group IVB metal oxycation-containing compound(s); (2) reducing the silver to metallic silver. - View Dependent Claims (22, 23)
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24. A process for the production of ethylene oxide comprising the steps of contacting ethylene in the vapor phase with an oxygen-containing gas at ethylene oxide forming conditions at a temperature ranging between about 180°
- C. and 330°
C. in the presence of a catalyst comprising a porous refractory support having deposited thereon a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium, and a promoting amount of Group IVB metal applied to the support in the form of oxycation-containing compound(s), wherein said Group IVB metal is selected from the group consisting of titanium, zirconium, and hafnium.
- C. and 330°
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25. A process for the epoxidation of olefins having no allylic hydrogen comprising the steps of contacting the olefins in the vapor phase with an oxygen-containing gas maintain at a ratio of olefin to oxygen in the range of 0.01 up to 20, at epoxide forming conditions at a temperature in the range of from about 75°
- C. to about 325°
C. in the presence of an organic halide, inorganic halides, acid halides, or elemental halogens, and a catalyst comprising a porous refractory support having deposited by impregnation thereon a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium, and a promoting amount of Group IVB metal applied to the support in the form of oxycation-containing compound(s);
wherein after the impregnation of the metals, the catalyst is put in intimate contact with a gas comprising a gas containing at least about 4 volume percent of hydrogen.
- C. to about 325°
Specification