Catalytic hydrogenation activity of a ZrNi/sub 3/ intermetallic alloy

Conference · Wed Jan 01 00:00:00 EST 1986

OSTI ID:5064290

Wright, R B; Jolley, J G; Owens, M S; Cocke, D L

The catalytic hydrogenation activity of a ZrNi/sub 3/ intermetallic alloy has been determined and has been found to be more active than either pure Ni or Pt for the hydrogenation of ethylene to ethane. The ZrNi/sub 3/, prepared by arc melting, was powdered and sieved (-200, +325 mesh) and tested in a microcatalytic reactor. Ni and Pt were also studied. Results indicate that from 30 to 120/sup 0/C the relative hydrogenation activities are ZrNi/sub 3/ > Pt > Ni for this reaction. Over this temperature range the apparent activation energies were found to be: ZrNi/sub 3/ = 7.1 kcal/mole; Pt = 11.5 kcal/mole; and Ni = 7.0 kcal/mole. Above approx.100/sup 0/C the activity of the ZrNi/sub 3/ begins to decline (as does that of Pt from previous studies). Upon pretreating the ZrNi/sub 3/ in an O/sub 2//He stream at 400/sup 0/C for two hours followed by a two-hour treatment in H/sub 2/ at 400/sup 0/C the activity increased and the apparent activation energy decreased to 0.75 kcal/mole. A further treatment at 550/sup 0/C caused the apparent activation energy to decrease to 0.40 kcal/mole. Both of these Q/sub 2/ treatments also resulted in an enhanced stability of the alloy with regard to its time-on-stream activity and in its activity temperature maximum being extended to approx.140/sup 0/C. The catalytic activity of ZrNi/sub 3/ is due to an O/sub 2/ induced decomposition into a NiO/ZrO/sub 2/ mixture residing on an inner core of ZrNi/sub 3/ alloy. Upon reduction the active catalyst is reduced Ni dispersed on ZrO/sub 2/ which, in turn, is present as a thin film on the ZrNi/sub 3/ core.

• Research Organization: Idaho National Engineering Lab., Idaho Falls (USA); EG and G Idaho, Inc., Idaho Falls (USA); Texas A and M Univ., College Station (USA). Dept. of Chemistry
• DOE Contract Number: AC07-76ID01570
• OSTI ID: 5064290
• Report Number(s): EGG-M-27986; CONF-861019-8; ON: DE87001435
• Resource Relation: Conference: 10. international vacuum congress and 6. international conference on solid surfaces and the 33. national symposium of the American Vacuum Society, Baltimore, MD, USA, 27 Oct 1986; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ETHYLENE
HYDROGENATION
NICKEL
CATALYTIC EFFECTS
NICKEL BASE ALLOYS
PLATINUM
ZIRCONIUM ALLOYS
ACTIVATION ENERGY
HEAT TREATMENTS
INTERMETALLIC COMPOUNDS
OXYGEN
ALKENES
ALLOYS
CHEMICAL REACTIONS
ELEMENTS
ENERGY
HYDROCARBONS
METALS
NICKEL ALLOYS
NONMETALS
ORGANIC COMPOUNDS
PLATINUM METALS
TRANSITION ELEMENTS
360104* - Metals & Alloys- Physical Properties
400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)