Chemistry of HO/sub 2/NO/sub 2/ and the photochemistry of the HO/sub x/-NO/sub x/-CO/sub x/ system

Technical Report · Fri Aug 01 04:00:00 EDT 1980

OSTI ID:6742639

Littlejohn, D

The objectives of this work were: (1) to investigate formation and destruction reactions of peroxynitric acid, HO/sub 2/NO/sub 2/, particularly formation by the gas phase reaction of H/sub 2/O/sub 2/ and N/sub 2/O/sub 5/, and destruction by attack of OH radical, and (2) to study the photochemistry and kinetics of the HO/sub x/-NO/sub x/-CO/sub x/ system by observing the response of species to photolytic light in a mixture of H/sub 2/O/sub 2/, NO/sub 2/, CO and O/sub 2/. Investigations were done using infrared spectroscopy to observe the behavior of species involved with the reactions of interest. Several techniques were used, including expansion of reactants into an evacuated cell, static cell decays under constant illumination, and periodic of flow systems. Infrared absorption cross sections were obtained for CO, CO/sub 2/, NO, NO/sub 2/, N/sub 2/O/sub 5/, HNO/sub 3/, H/sub 2/O/sub 2/, and H/sub 2/O. The spectroscopic measurements were used to derive kinetic information on the systems under study. The reaction of H/sub 2/O/sub 2/ with N/sub 2/O/sub 5/ has previously been studied only in the liquid phase. This study investigated the reaction of gaseous H/sub 2/O/sub 2/ and N/sub 2/O/sub 5/ in the temperature range of 253/sup 0/K to 283/sup 0/K and a pressure range of 10 torr to 80 torr. The reaction occurred primarily heterogeneously in the apparatus in which it was studied. The upper limit for the bimolecular reaction giving the products H/sub 2/O/sub 2/ + N/sub 2/O/sub 5/ ..-->.. HNO/sub 4/ + HNO/sub 3/ was determined to be k < 1 x 10/sup -18/cm/sup 3/ molecule/sup -1/ second/sup -1/. The products of the reaction of OH with HNO/sub 4/ were determined to be OH + HNO/sub 4/ ..-->.. H/sub 2/O + NO/sub 2/ + O/sub 2/ and the rate constant for the reaction was found to be 2.9 +- 1.0 x 10/sup -12/ cm/sup 3/ molecule/sup -1/ over the temperature range of 263/sup 0/K to 283/sup 0/K. The decay profiles of species in the static cell photolysis of NO/sub 2/, H/sub 2/O/sub 2/ and CO in 0.1 and 1.0 atmosphere of O/sub 2/ were observed and compared with numerical simulations.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6742639
• Report Number(s): LBL-11480
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical &amp; Physicochemical Properties
400500 -- Photochemistry
ABSORPTION SPECTROSCOPY
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMPARATIVE EVALUATIONS
DATA
DECOMPOSITION
ELEMENTS
EXPERIMENTAL DATA
FLUIDS
GASES
HYDROGEN COMPOUNDS
HYDROGEN PEROXIDE
HYDROXYL RADICALS
INFORMATION
INFRARED SPECTRA
INORGANIC ACIDS
KINETICS
LOW PRESSURE
MATHEMATICS
MEDIUM TEMPERATURE
NITRIC ACID
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN DIOXIDE
NITROGEN OXIDES
NONMETALS
NUMERICAL ANALYSIS
NUMERICAL DATA
OXIDES
OXYGEN
OXYGEN COMPOUNDS
OZONE
PEROXIDES
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADICALS
REACTION KINETICS
SPECTRA
SPECTROSCOPY
SYNTHESIS
WATER