Iron salt aerosols are one proposed method of enhanced atmospheric methane oxidation which involves lofting iron-based particles into the atmosphere (e.g. from planes or ships) to enhance atmospheric chlorine radicals, a natural methane sink.
Winds over the Sahara raise dust into the troposphere and disperse it over the Atlantic. A 2023 study suggests that this has contributed to natural atmospheric methane oxidation.
Iron salt aerosols are being studied for the potential of iron(III) chloride (FeCl) to catalyze chlorine radical production. Chlorine atoms are produced by photolysis from the FeCl stemming from iron-containing airborne dust aerosol particles in the oceanic boundary layer.
:FeCl + hv → FeCl + Cl
The chlorine atoms initiate methane oxidation:
:CH + Cl → HCl + CH
The resulting methyl radical is unstable and oxidises naturally to CO and water:
:3.5O + 2CH → 2CO + 3HO