Dinitrosyl intermediate for N{sub 2}O formation from reaction of NO on Mo(110)

Journal Article · Wed Oct 01 04:00:00 EDT 1997 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.474303· OSTI ID:632536

Queeney, K T; Friend, C M ^[1]

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1. Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138 (United States)

The adsorption and subsequent reaction of nitric oxide (NO) on Mo(110) has been studied by temperature programmed reaction, electron energy loss, and infrared reflectance absorbance spectroscopies. The predominant reaction pathway for a saturated NO overlayer is dissociation to atomic nitrogen and oxygen; in fact, for low NO coverages, dissociation is the only reaction and largely takes place below 300 K. At NO coverages above 65{percent} of {theta}{sub sat}, evolution of N{sub 2}O, N{sub 2}, and NO is also observed at low temperature. Temperature programmed reaction of isotopically mixed overlayers demonstrates that N{sub 2}O formation occurs via reaction of two intact NO molecules, suggestive of a dimeric surface intermediate. Electron energy loss and infrared spectroscopies identify three {nu}(NO) features which are assigned to three distinct species; the frequencies of the {nu}(NO) peaks in the infrared spectrum of a saturated {sup 14}NO overlayer at 100 K are 1860, 1821, and 1720thinspcm{sup {minus}1}. The 1860 and 1720thinspcm{sup {minus}1} features are assigned to monomeric NO. Based on the infrared spectrum of a mixed overlayer of {sup 14}NO and {sup 15}NO, and on comparison to reference spectra of NO adsorbed on MoO{sub 3}, the 1821thinspcm{sup {minus}1} peak is identified as {nu}{sub s}(NO) of a surface dinitrosyl complex, i.e., two NO molecules bound to one Mo site. The weakly bound NO with the stretch frequency of 1860thinspcm{sup {minus}1} is associated with NO desorption, while the dinitrosyl leads to low-temperature N{sub 2} and N{sub 2}O formation and some dissociation. {copyright} {ital 1997 American Institute of Physics.}

• DOE Contract Number: FG02-84ER13289
• OSTI ID: 632536
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 16 Vol. 107; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ADSORPTION
CHEMICAL REACTIONS
ELECTRON SPECTROSCOPY
INFRARED SPECTRA
MOLYBDENUM
NITRIC OXIDE
NITROUS OXIDE
REACTION INTERMEDIATES
SPECTRAL REFLECTANCE
SURFACE PROPERTIES
SYNTHESIS
THERMAL ANALYSIS