Selective epoxidation of ethylene catalyzed by silver. Mechanistic details revealed by single-crystal studies

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6822886

Campbell, C T

The selective oxidation of ethylene to ethylene epoxide (C/sub 2/H/sub 4/ + 1/2 O/sub 2/ ..-->.. C/sub 2/H/sub 4/O) over Ag is a simple prototype for the entire class of kinetically-controlled, selective oxidation reactions. We have studied the steady-state kinetics and selectivity of this reaction on clean, well-characterized single-crystal surfaces of silver by using a special apparatus which allows rapid (approx. 20 s) transfer between a high-pressure catalytic microreactor and an ultra-high vacuum surface analysis (AES, XPS, LEED, TDS) chamber. The results of some of our recent studies of this reaction are reviewed. These single-crystal studies have provided considerable new insight into: the reaction pathway through molecularly adsorbed O/sub 2/ and C/sub 2/H/sub 4/, the structural sensitivity of real silver catalysts, and the role of chlorine adatoms in promoting catalyst selectivity.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6822886
• Report Number(s): LA-UR-84-1041; CONF-840805-2; ON: DE84009987
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKENES
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTIONS
CHLORINE
CRYSTALS
ELEMENTS
ETHYLENE
HALOGENS
HYDROCARBONS
METALS
MONOCRYSTALS
NONMETALS
ORGANIC COMPOUNDS
OXIDATION
SILVER
TRANSITION ELEMENTS