title: Desorption of polycyclic aromatic hydrocarbons from soot surface: pyrene and fluoranthene.
abstract: The kinetics of thermal desorption of two four-ring polycyclic aromatic hydrocarbons, fluoranthene, and pyrene from well-characterized laboratory-generated kerosene soot surface was studied over the temperature range 260-320 K in a low-pressure flow reactor combined with an electron-impact mass spectrometer. Two methods were used to measure the desorption rate constants: monitoring of the surface-bound fluoranthene and pyrene decays due to desorption using off-line HPLC measurements of their concentrations in soot samples, and monitoring of the desorbed molecules in the gas phase using in situ mass spectrometric detection. Results obtained with the two methods were in good agreement and yielded the following Arrhenius expressions for the desorption rate constants: k(des) (fluoranthene) = 4 x 10(14) exp[-(93900 +/- 1700)/RT] and k(des) (pyrene) = 6 x 10(14) exp[-(95200 +/- 1800)/RT] (k(des) are in units of s(-1), and activation energies are in J mol(-1)). In addition, the combined uptake coefficient of fluoranthene and pyrene on soot (calculated using specific surface area) was estimated to be near 5 x 10(-3) at T = 310 K.
authors.affiliation: Institut de Combustion, Aerothermique, Reactivite et Environnement, CNRS, 45071 Orleans Cedex 2, France.
authors.forename: Angélique
authors.initials: A
authors.lastname: Guilloteau
authors.forename: Mai Lan
authors.initials: ML
authors.lastname: Nguyen
authors.forename: Yuri
authors.initials: Y
authors.lastname: Bedjanian
authors.forename: Georges
authors.initials: G
authors.lastname: Le Bras
mesh_terms: D000327:Adsorption; D005449:Fluorenes / Q000737:chemistry*; D007648:Kerosene; D007700:Kinetics; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D011721:Pyrenes / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D005449:Fluorenes; D007648:Kerosene; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; C007738:fluoranthene; C030984:pyrene