title: Chemical characterization of diesel and hydrotreated vegetable oil (HVO) soot after reactive gas probing using diffuse reflectance FTIR spectroscopy (DRIFTS).
abstract: A chemical characterization of diesel and hydrotreated vegetable oil (HVO) soot has been developed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) before and after the reaction with different probe gases. Samples were generated under combustion conditions corresponding to an urban operation mode of a diesel engine and were reacted with probe gas-phase molecules in a Knudsen flow reactor. Specifically, NH2OH, O3and NO2were used as reactants (probes) and selected according to their reactivities towards specific functional groups on the sample surface. Samples of previously ground soot were diluted with KBr and were introduced in a DRIFTS accessory. A comparison between unreacted and reacted soot samples was made in order to establish chemical changes on the soot surface upon reaction. It was concluded that the interface of diesel and HVO soot before reaction mainly consists polycyclic aromatic hydrocarbons, nitro and carbonyl compounds, as well as ether functionalities. The main difference between both soot samples was observed in the band of the C=O groups that in diesel soot was observed at 1719 cm-1but not in HVO soot. After reaction with probe gases, it was found that nitro compounds remain on the soot surface, that the degree of unsaturation decreases for reacted samples, and that new spectral bands such as hydroxyl groups are observed.
authors.affiliation: Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Tapia
authors.affiliation: Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain. Sagrario.Salgado@uclm.es.
authors.forename: M S
authors.initials: MS
authors.lastname: Salgado
authors.affiliation: Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain.
authors.forename: M P
authors.initials: MP
authors.lastname: Martín
authors.affiliation: Grupo de Combustibles y Motores, Escuela Técnica Superior de Ingenieros Industriales, Universidad de Castilla La Mancha, Avda. Camilo José Cela 10, 13071, Ciudad Real, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Rodríguez-Fernández
authors.affiliation: Labor für Atmosphärenchemie (LAC), Paul Scherrer Institute (PSI), OBBA006, 5232, Villigen PSI, Switzerland.
authors.forename: M J
authors.initials: MJ
authors.lastname: Rossi
authors.affiliation: Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Cabañas
mesh_terms: D005740:Gases / Q000737:chemistry; D010938:Plant Oils / Q000032:analysis / Q000737:chemistry; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry; D053260:Soot / Q000032:analysis / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D005740:Gases; D010938:Plant Oils; D011084:Polycyclic Aromatic Hydrocarbons; D053260:Soot
keywords: Alternative fuel; Diesel fuel; Infrared spectroscopy; Particulate matter; Surface composition