Stoichiometry and poisoning by sulfur of hydrogen, oxygen, and carbon monoxide chemisorption on unsupported nickel

Journal Article · Mon Feb 28 23:00:00 EST 1977 · J. Catal.; (United States)

DOI:https://doi.org/10.1016/0021-9517(77)90217-2· OSTI ID:7307842

Pannell, R B; Chung, K S; Bartholomew, C H

Hydrogen chemisorption and BET measurements (argon and nitrogen) have been used to determine the stoichiometry of hydrogen adsorption on nickel powder. The hydrogen adsorption isotherms were measured at room temperature and at 200/sup 0/C. The experimental results indicate that the H/Ni/sub 3/ ratio on unsupported nickel is 1 : 1 at both temperatures. Nickel powder samples were also poisoned with H/sub 2/S at a level of 5 ppm for 6 hr. The samples poisoned with H/sub 2/S suffer no loss in overall surface area determined by BET measurements; however, hydrogen chemisorption is substantially reduced, although less at 200/sup 0/C. Data for CO adsorption on a nickel powder at 25/sup 0/C show a CO/H value of 2.09 suggesting surface carbonyl formation. After evacuation at 25/sup 0/C, however, the ratio decreases to 1.16, showing that reversible adsorption--desorption occurs. At -83/sup 0/C, a value of CO/H of 0.54 is obtained both before and after evacuation indicating no reversible adsorption. The number of CO molecules irreversibly adsorbed per surface nickel atom is 0.54. Data for adsorption of oxygen at 25/sup 0/C show that three oxygen atoms adsorb for every nickel surface atom and that approximately one of three oxygen atoms can interact with but not be removed by titration with hydrogen at 25/sup 0/C.

• Research Organization: Brigham Young Univ., Provo, UT
• OSTI ID: 7307842
• Journal Information: J. Catal.; (United States), Journal Name: J. Catal.; (United States) Vol. 46:3; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISORPTION
CRYOGENIC FLUIDS
ELEMENTS
FLUIDS
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
KINETICS
METALS
NICKEL
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
POISONING
REACTION KINETICS
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SULFIDES
SULFUR COMPOUNDS
SURFACE PROPERTIES
TRANSITION ELEMENTS