The OH oxidation of α-pinene under both lowand high-NOx environments was studied in the Caltech atmospheric chambers. Ozone was kept low to ensure OH was the oxidant. The initial α-pinene concentration was 20–50 ppb to ensure that the dominant peroxy radical pathway under low-NOx conditions is reaction with HO2, produced from reaction of OH with H2O2, and under high-NOx conditions, reactions wi...

The chemical composition of nighttime urban fog has been investigated using a hybrid kinetic and equilibrium model. Extremely high acidity may be imparted to the droplets by condensation and growth on acidic condensation uclei or by in situ S(IV) oxidation. Important oxidants of S(IV) were found to be 02 as catalyzed by Fe(III) and Mn(II), H20:, and 03. Formation of hydroxymethanesulfonate ion ...

Oxidation of histidine by (1)O2 is an important process associated with oxidative damage to proteins during aging, diseases and photodynamic therapy of tumors and jaundice, and photochemical transformations of biological species in the troposphere. However, the oxidation mechanisms and products of histidine differ dramatically in these related environments which range from the gas phase through...

Ordered, extra-large mesopores with highly loaded gold nanoparticles (AuNPs) exhibits unique sintering- and coking-resistant properties in gas-phase, cyclohexanol selective aerobic oxidation.

Methane is an abundant resource and its direct conversion into value-added chemicals has been attractive subject for efficient utilization. This method can be more than the present energy-intensive indirect of methane via syngas, a mixture CO H2. Among various approaches conversion, selective oxidation oxygenates (e.g., methanol formaldehyde) particularly promising because it proceed at low tem...

Under technologically relevant oxygen-rich conditions, the reaction mechanism of CO oxidation over transition metals can be complicated by the formation of oxides. Questions of whether the active surface for CO oxidation is a pristine metal, a surface oxide, or a bulk oxide is still under active debate. In this study, density functional theory calculations are used to model CO oxidation on the ...

Oxidized mercury species may be formed in combustion systems through gas-phase reactions between elemental mercury and halogens, such as chorine or bromine. Injection of bromine compounds or brominated sorbents have been shown to affect mercury speciation and removal in coal-fired power plants. This study examines how bromine species affect mercury oxidation in the gas-phase. Experiments were c...

Ozone-driven chemistry is a source of indoor secondary pollutants of potential health concern. This study investigates secondary air pollutants formed from reactions between constituents of household products and ozone. Gas-phase product emissions were introduced along with ozone at constant rates into a 198-L Teflon-lined reaction chamber. Gas-phase concentrations of reactive terpenoids and ox...