Abstract A sliver-supported catalyst is prepared by immersing a carrier of inert porous particles having an average diameter not larger than 3/16 inch, an average pore diameter of about 10-70 microns, and a surface area less than one square meter per gram in an aqueous solution of a silver salt whereby said particles are impregnated with said solution, separating and drying the impregnated particles, and activating the dried particles by heating in air at a temperature sufficient to decompose the sliver salt. Silica-alumina support particles and a silver salt of an organic carboxylic acid such as lactic acid are preferably used in the process. Optionally, an alkaline earth promoter is added to the silver salt solution. The catalyst product is used in the production of ethylene oxide by the vapor phase oxidation of ethylene.
A process according to claim 1 wherein the step of activating is carried out by heating the dried particles gradually to a temperature of 200* to 300*C. and thereafter maintaining said temperature for a period of time sufficient to decompose said silver salt.
Claim 2
Dependent Claim
22 words
A process according to claim 1 wherein the aqueous solution formed comprises 25 to 80 percent by weight of said silver salt.
Claim 3
Dependent Claim
26 words
A process according to claim 3 wherein said aqueous solution is formed by the addition of silver oxide to an aqueous solution of a carboxylic acid.
Claim 4
Dependent Claim
12 words
A process according to claim 4 wherein said acid is lactic acid.
Claim 5
Dependent Claim
34 words
A process according to claim 1 wherein the aqueous solution formed comprises an effective amount of an oxidizing agent to prevent reduction of said silver salt and precipitation of metallic silver prior to impregnation.
Claim 6
Dependent Claim
16 words
A process according to claim 1 wherein the aqueous solution formed comprises an alkaline earth promoter.
Claim 7
Dependent Claim
36 words
A process according to claim 1 wherein the step of drying is carried out by heating the separated particles in air at a temperature of 20* to 175*C. for a period of at least 10 hours.