Patent ID: 8765633

Claim:
A catalyst for the production of ethylene oxide comprising silver and a reaction promoter supported on a porous carrier comprising α-alumina as a main component, characterized in that; the relative standard deviation of the silver supporting rate on each particle of the catalyst is between 0.001 or more and 0.1 or less, indicating a variation of silver content among the catalyst particles, the value being determined by the following formula (1): ( Relative ⁢ ⁢ standard ⁢ ⁢ deviation ⁢ ⁢ of ⁢ ⁢ silver ⁢ ⁢ supporting ⁢ ⁢ rate ) = ( Standard ⁢ ⁢ deviation ⁢ ⁢ of ⁢ ⁢ silver ⁢ ⁢ ⁢ supporting ⁢ ⁢ rate ) ( Average ⁢ ⁢ silver ⁢ ⁢ supporting ⁢ ⁢ rate ) ( 1 ) wherein the standard deviation of silver supporting rate is determined by the following formula (2): ( Standard ⁢ ⁢ deviation ⁢ ⁢ of ⁢ ⁢ silver ⁢ ⁢ supporting ⁢ ⁢ rate ) = N ⁢ ∑ Xn 2 - ( ∑ Xn ) 2 N ⁡ ( N - 1 ) ( 2 ) wherein N represents the number of catalyst particles for which the silver supporting rate is measured, N is greater than or equal to 30, and Xn represents the silver supporting rate of each particle; and the average silver supporting rate is an arithmetic mean of the silver supporting rates of N particles.