Pulse radiolysis of supercritical water II. Reaction of nitrobenzene with hydrated electrons and hydroxyl radicals.

Journal Article · Fri Dec 26 00:00:00 EST 2003 · J. Phys. Chem. A

OSTI ID:961058

Marin, T W; Cline, J A; Bartels, D M; Jonah, C D; Takahashi, K

The rate constants for the reactions of nitrobenzene with the hydroxyl radical (OH{sup {sm_bullet}}) and hydrated electron ((e{sup -}){sub aq}) in water have been measured from room temperature to 400 {sup o}C using electron pulse radiolysis and transient absorption spectroscopy. The diffusion-limited reaction of nitrobenzene with (e{sup 0}){sub aq} exhibits temperature-insensitive activation energy up to 300 {sup o}C, indicating that the activation energy for electron diffusion remains high over this range. The (e{sup -}){sub aq} reactivity is explained as a long-range electron transfer, and the results are interpreted in terms of extended Marcus theory and Smoluchowski relationships. At 380 {sup o}C, the rate constant has a density dependence similar to that previously reported for other (e{sup -}){sub aq} scavenging reactions. The reaction rate of nitrobenzene with OH{sup {sm_bullet}} is very insensitive to temperature from room temperature up to 300 {sup o}C, in agreement with previous studies. Above 300 {sup o}C, the rate constant increases as the critical temperature is approached and exceeded. Time-resolved electronic absorption spectra of the nitrobenzene radiolysis transients reveal complex kinetics involving multiple absorbing species.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC); FOR; OGA
• DOE Contract Number: DE-AC02-06CH11357
• OSTI ID: 961058
• Report Number(s): ANL/CHM/JA-44238; JPCAFH; TRN: US1003246
• Journal Information: J. Phys. Chem. A, Vol. 106, Issue 51 ; Dec. 26, 2003; ISSN 1089-5639
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
ABSORPTION SPECTRA
ABSORPTION SPECTROSCOPY
ACTIVATION ENERGY
CRITICAL TEMPERATURE
DENSITY
DIFFUSION
ELECTRON TRANSFER
ELECTRONS
HYDRATION
HYDROXYL RADICALS
KINETICS
NITROBENZENE
PULSES
RADIOLYSIS
RANGE
REACTION KINETICS
REACTIVITY
SCAVENGING
SOLVATED ELECTRONS
SUPERCRITICAL STATE
TRANSIENTS
WATER