J 2013

Rate Acceleration of the Heterogeneous Reaction of Ozone with a Model Alkene at the Air-Ice Interface at Low Temperatures

RAY, Debajyoti, Joseph K'ekuboni MALONGWE and Petr KLÁN

Basic information

Original name

Rate Acceleration of the Heterogeneous Reaction of Ozone with a Model Alkene at the Air-Ice Interface at Low Temperatures

Authors

RAY, Debajyoti (356 India, belonging to the institution), Joseph K'ekuboni MALONGWE (180 Democratic Republic of the Congo, belonging to the institution) and Petr KLÁN (203 Czech Republic, guarantor, belonging to the institution)

Edition

Environmental Science and Technology, Columbus, Ohio, USA, American Chemical Society, 2013, 0013-936X

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10401 Organic chemistry

Country of publisher

United States of America

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 5.481

RIV identification code

RIV/00216224:14310/13:00066641

Organization unit

Faculty of Science

UT WoS

000321521400009

Keywords in English

Photochemistry; Ice; Snow; Ozone

Tags

Tags

International impact, Reviewed
Změněno: 1/4/2015 22:15, prof. RNDr. Petr Klán, Ph.D.

Abstract

V originále

The kinetics of the ozonation reaction of 1,1-diphenylethylene (DPE) on the surface of ice grains (also called "artificial snow"), produced by shock-freezing of DPE aqueous solutions or DPE vapor-deposition on pure ice grains, was studied in the temperature range of 268 to 188 K. A remarkable and unexpected increase in the apparent ozonation rates with decreasing temperature was evaluated using the Langmuir-Hinshelwood and Eley-Rideal kinetic models, and by estimating the apparent specific surface area of the ice grains. We suggest that an increase of the number of surface reactive sites, and possibly higher ozone uptake coefficients are responsible for the apparent rate acceleration of DPE zonation at the air ice interface at lower temperatures. The increasing number of reactive sites is probably related to the fact that organic molecules are displaced more to the top of a disordered interface (or quasi liquid) layer on the ice surface, which makes them more accessible to the gas phase reactants. The effect of NaCl as a cocontaminant on ozonation rates was also investigated. The environmental implications of this phenomenon for natural ice/snow are discussed. DPE was selected as an example of environmentally relevant species which can react with ozone. For typical atmospheric ozone concentrations in polar areas (20 ppbv), we estimated that its half-life on the ice surface would decrease from similar to 5 days at 258 K to similar to 13 h at 188 K at submonolayer DPE loadings.

Links

ED0001/01/01, research and development project
Name: CETOCOEN
GAP503/10/0947, research and development project
Name: Důsledky fotochemické aktivity organických polutantů v polárních oblastech
Investor: Czech Science Foundation
LM2011028, research and development project
Name: RECETOX ? Národní infrastruktura pro výzkum toxických látek v prostředí
Investor: Ministry of Education, Youth and Sports of the CR