scholarly journals Production of stabilized Criegee intermediates and peroxides in the gas phase ozonolysis of alkenes: 2. Asymmetric and biogenic alkenes

2001 ◽  
Vol 106 (D24) ◽  
pp. 34143-34153 ◽  
Author(s):  
Alam S. Hasson ◽  
Andy W. Ho ◽  
Keith T. Kuwata ◽  
Suzanne E. Paulson
Keyword(s):  
Gas Phase ◽  
Criegee Intermediates ◽  
Stabilized Criegee Intermediates

scholarly journals Oxidation of SO<sub>2</sub> by stabilized Criegee intermediate (sCI) radicals as a crucial source for atmospheric sulfuric acid concentrations

2013 ◽  
Vol 13 (7) ◽  
pp. 3865-3879 ◽  
Author(s):  
M. Boy ◽  
D. Mogensen ◽  
S. Smolander ◽  
L. Zhou ◽  
T. Nieminen ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Gas Phase ◽  
Oxidation Mechanism ◽  
Ground Level ◽  
Reaction Rates ◽  
Rate Coefficients ◽  
Dimensional Model ◽  
Sulfuric Acid Production ◽  
Criegee Intermediates ◽  
Stabilized Criegee Intermediates

Abstract. The effect of increased reaction rates of stabilized Criegee intermediates (sCIs) with SO2 to produce sulfuric acid is investigated using data from two different locations, SMEAR II, Hyytiälä, Finland, and Hohenpeissenberg, Germany. Results from MALTE, a zero-dimensional model, show that using previous values for the rate coefficients of sCI + SO2, the model underestimates gas phase H2SO4 by up to a factor of two when compared to measurements. Using the rate coefficients recently calculated by Mauldin et al. (2012) increases sulfuric acid by 30–40%. Increasing the rate coefficient for formaldehyde oxide (CH2OO) with SO2 according to the values recommended by Welz et al. (2012) increases the H2SO4 yield by 3–6%. Taken together, these increases lead to the conclusion that, depending on their concentrations, the reaction of stabilized Criegee intermediates with SO2 could contribute as much as 33–46% to atmospheric sulfuric acid gas phase concentrations at ground level. Using the SMEAR II data, results from SOSA, a one-dimensional model, show that the contribution from sCI reactions to sulfuric acid production is most important in the canopy, where the concentrations of organic compounds are the highest, but can have significant effects on sulfuric acid concentrations up to 100 m. The recent findings that the reaction of sCI + SO2 is much faster than previously thought together with these results show that the inclusion of this new oxidation mechanism could be crucial in regional as well as global models.

scholarly journals The influences of ammonia on aerosol formation in the ozonolysis of styrene: roles of Criegee intermediate reactions

2018 ◽  
Vol 5 (5) ◽  
pp. 172171 ◽  
Author(s):  
Qiao Ma ◽  
Xiaoxiao Lin ◽  
Chengqiang Yang ◽  
Bo Long ◽  
Yanbo Gai ◽  
...  
Keyword(s):  
Gas Phase ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Organic Aerosol ◽  
Aerosol Formation ◽  
Gas Phase Reactions ◽  
Aerosol Composition ◽  
Theoretical Methods ◽  
Criegee Intermediates ◽  
Secondary Ozonide

The influences of ammonia (NH 3 ) on secondary organic aerosol (SOA) formation from ozonolysis of styrene have been investigated using chamber experiments and quantum chemical calculations. With the value of [O 3 ] 0 /[styrene] 0 ratios between 2 and 4, chamber experiments were carried out without NH 3 or under different [NH 3 ]/[styrene] 0 ratios. The chamber experiments reveal that the addition of NH 3 led to significant decrease of SOA yield. The overall SOA yield decreased with the [NH 3 ] 0 /[styrene] 0 increasing. In addition, the addition of NH 3 at the beginning of the reaction or several hours after the reaction occurs had obviously different influence on the yield of SOA. Gas phase reactions of Criegee intermediates (CIs) with aldehydes and NH 3 were studied in detail by theoretical methods to probe into the mechanisms behind these phenomena. The calculated results showed that 3,5-diphenyl-1,2,4-trioxolane, a secondary ozonide formed through the reactions of C 6 H 5 ĊHOO· with C 6 H 5 CHO, could make important contribution to the aerosol composition. The addition of excess NH 3 may compete with aldehydes, decreasing the secondary ozonide yield to some extent and thus affect the SOA formation.

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