Coordination chemistry of metal surfaces. 2. Chemistry of CH/sub 3/CN and CH/sub 3/NC on nickel surfaces

Journal Article · Wed Feb 25 04:00:00 EST 1981 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00394a007· OSTI ID:6603853

Friend, C M; Stein, J; Muetterties, E L

The Ni surfaces studied were the low Miller index planes (111), (110), and (100) and the stepped and stepped-kinked planes 9(111) x (111) and 7(111) x (310), respectively. Effects of surface C, S, and O/sub 2/ contaminant atoms on the chemistry were examined. CH/sub 3/CN was weakly and reversibly bound on the (111), stepped, and stepped-kinked surface and was probably oriented with the CN vector normal to the flat surface sections. The thermal desorption temperature was about 90/sup 0/C. Some irreversible decomposition, probably focused at step or kink sites, was observed in the thermal desorption experiments. CH/sub 3/CN on the super-stepped (110) surface largely underwent decomposition on heating; very little reversible chemisorption was observed. Binding of the nitrile on the (100) surface was significantly different than for the more closely packed (111) surface; the thermal desorption temperature maximum was about 20/sup 0/C higher than for Ni(111)-NCCH/sub 3/. The Ni(100)-NCCH/sub 3/ state was ordered, c(2 x 2); here the nitrile nitrogen atom may lie in the fourfold sites. Labeling studies of the CH/sub 3/CN chemisorption showed there was no reversible bond breaking process from 20 to approx. 100/sup 0/C. Neither carbon nor sulfur altered this Ni surface-CH/sub 3/CN chemistry. Methyl isocyanide was strongly bound to all the Ni surfaces and essentially could not be thermally desorbed from the clean surfaces; decomposition to H/sub 2/(g) and N/sub 2/(g) prevailed. Sulfur contaminant atoms on the nickel surfaces did not alter this chemistry but C did. CH/sub 3/NC chemisorbed on C-containing Ni(111), Ni(9(111) x (111)), and Ni(7(111) x (310)) surfaces rearranged on heating and desorbed as CH/sub 3/CN at approx. 90/sup 0/C. The chemistry was similar on the C-containing (110) and (100) surfaces to that for CH/sub 3/CN on the respective Ni(110)-C and Ni(100)-C surfaces.

• Research Organization: Lawrence Berkeley Lab., CA
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6603853
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 103:4; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ADSORPTION
BINDING ENERGY
CARBON
CHEMICAL REACTIONS
CHEMISORPTION
COORDINATION NUMBER
CRYSTALS
DATA
DECOMPOSITION
DESORPTION
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY
ESTERS
EXPERIMENTAL DATA
INFORMATION
ISOCYANIC ACID ESTERS
ISOMERIZATION
LABELLING
METALS
MONOCRYSTALS
NICKEL
NITRILES
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SULFUR
SURFACE PROPERTIES
SURFACES
TEMPERATURE DEPENDENCE
TRANSITION ELEMENTS