Impurity modification of surface catalyzed reactions: Methanation over phosphided nickel

Conference · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5985780

Goodman, D W; Kiskinaya, M

Single crystal catalysts have been used to investigate the methanation reaction over phosphided nickel surfaces. The apparatus used in these studies allows for catalyst preparation and surface characterization in ultrahigh vacuum (UHV) with an in vacuo transfer to a second UHV chamber designed for kinetics at elevated pressures. Kinetic studies on single crystals of nickel have shown the effect of sulfur to be strongly nonlinear where one sulfur atom effectively deactivates ten or more nickel surface atoms. These studies have addressed the role of ensemble effects as opposed to electronic effects in the deactivation mechanism. Studies similar to the previous ones for sulfur have been carried out for phosphorus. These data show phosphorus to be much less effective in attenuating the nickel catalytic activity for methanation. The reduced severity of the poisoning by phosphorus is attributed to its lower electronegativity. These results are consistent with an electronic effect playing a significant role in the poisoning of nickel methanation activity by sulfur.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5985780
• Report Number(s): CONF-841121-
• Country of Publication: United States
• Language: English

Related Subjects

090121* -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
ALKANES
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CRYSTALS
ELECTRONEGATIVITY
ELEMENTS
HYDROCARBONS
IMPURITIES
KINETICS
METHANATION
METHANE
MONOCRYSTALS
NICKEL COMPOUNDS
NICKEL PHOSPHIDES
NONMETALS
ORGANIC COMPOUNDS
PHOSPHIDES
PHOSPHORUS
PHOSPHORUS COMPOUNDS
PNICTIDES
REACTION KINETICS
SULFUR
SURFACES
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
ULTRAHIGH VACUUM