Alpha Alumina Support and Ethylene Oxide Catalyst Preparation (Ag/α-Al2O3) with High Dispersion of Nano-Silver Particles

The catalyst used for partial oxidation of ethylene to ethylene oxide is Ag/α-Al2O3 which its physicochemical properties، i. e.، surface area، pore volume، silver contents and their dispersion profoundly affect its catalytic performance. In this research، alpha alumina as catalyst support with surface area and pore volume of 0. 5- 1. 2 m2 g-1 and 0. 11– 0. 2 ml g-1، were prepared by physical mixing، grinding، extrusion and calcination. The deposition method of silver metal on catalyst support and the use of alkali metal during the catalyst preparation affect the silver particle dispersion on catalyst. In this work wetimpregnationmethod was used for catalyst preparation. Silver particles size، their percent dispersion and contents were determined using transmission electron microscope (TEM)، x-ray diffraction (XRD) and atomic absorption (AA). Results showed that the catalyst prepared in this work with the same silver content had higher silver percent dispersion compare tothe commercial type catalyst. Silver content، silver percent dispersion and silver particles size for catalyst prepared in this work and the commercial catalyst were in the range of، 5. 25-14. 30، 14. 3 wt%; 34. 40-19. 61، 4. 31 % and 67. 3-112. 1، 90. 3 nm.