The
gas phase and heterogeneous reaction on mineral dust aerosols
of trace gases could significantly affect the tropospheric oxidation
capacity and aerosol composition of the atmosphere. In this work,
the OH radical-initiated oxidation of a hydrofluoroolefin, HFO-1234zc,
and subsequent reaction of favorable intermediates with other reactive
species, such as O2, HO2, and NO
x
(x = 1–2) radicals, were
studied, and the role of mineral dust in the form of silicate clusters
on the reaction mechanism and rate constant was studied. In the gas
phase, OH radical addition to HFO-1234zc is kinetically more favorable
than the H-atom abstraction reaction. The calculated reaction energy
barrier and thermochemical parameters show that both the initial reactions
are more feasible on silicate clusters. Thus, silicates can act as
chemical sinks for trapping of hydrofluoroolefins (HFOs). It is found
that both gas-phase and heterogeneous reactions are responsible for
the transformation of HFOs into fluorinated compounds in the atmosphere.
Further, the results show that the ozone creation potential of HFO-1234zc
is low, and few of the products are harmful to aquatic organisms.
This study provides new insights on the formation of toxic pollutants
from the oxidation of HFO-1234zc, which may have significant implications
in the troposphere.