Surface chemistry of hydrazine on Pt(111)

Diann J. Alberas, J. Kiss, Z. M. Liu, J. M. White

Research output: Contribution to journalArticle

69 Citations (Scopus)

Abstract

The thermal decomposition of hydrazine, N2H4, adsorbed on a Pt(111) surface at 60 K has been investigated by temperature programmed desorption (TPD), high resolution electron energy loss spectroscopy (HREELS), X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and temperature programmed secondary ion mass spectroscopy (TPSIMS). Condensed multilayer and chemisorbed states of hydrazine can be distinguished. Submonolayer hydrazine coverages start to decompose between 150 and 200 K by dissociation of NH, not NN, bonds. In TPD, H2, NH3, and N2 all peak near 310 K. N2 and NH2 desorb in processes limited by the rates of the reactions forming them. N2 is formed by an intramolecular process. No nitrogen containing species are detected above 400 K in HREELS or XPS. Depending on the surface coverage and temperature, dihydrogen desorption is probably limited by both the recombination rate and the rate of NH cleavage. We propose that: (1) the low temperature NH bond cleavage and the retention of NN bonds are facilitated by the chemisorption of N2H4 through both nitrogen atoms, and (2) relative to the N-metal bond, the H-metal bond is stronger on Pt(111). As a result, the barrier to NH cleavage is lowered much more than the barrier to NN cleavage, and the former is preferred.

Original languageEnglish
Pages (from-to)51-61
Number of pages11
JournalSurface Science
Volume278
Issue number1-2
DOIs
Publication statusPublished - Nov 1 1992

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Surface chemistry of hydrazine on Pt(111)'. Together they form a unique fingerprint.

  • Cite this