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Comment on "Liquid-Gas Interface of Iron Aqueous Solutions and Fenton Reagents"
Agustín J Colussi1, Shinichi Enami2
1California Institute of Technology, 1200 East California Blvd., Pasadena, California 91125, United States.
The Journal of Physical Chemistry Letters
|July 18, 2022
Summary
This study challenges findings on aqueous iron(II) ions reacting with gaseous hydrogen peroxide. The authors argue conclusions about undetected species are scientifically unsound.
Area of Science:
- Physical Chemistry
- Surface Science
- Spectroscopy
Background:
- A previous study reported no detectable products from aqueous Fe(II) reacting with gaseous H2O2 on water jets.
- The previous study concluded Fe(aq)2+ reacts with H2O2(g) at the interface, forming Fe3+ and HO• radicals.
- This conclusion was based on indirect evidence, as products were not directly observed.
Purpose of the Study:
- To critically evaluate the conclusions drawn from a previous study on the reaction between aqueous Fe(II) and gaseous H2O2.
- To highlight the limitations of inferring reaction products from the absence of detected species.
Main Methods:
- Theoretical analysis and scientific argumentation.
- Re-evaluation of spectroscopic data interpretation.
Main Results:
- The detection of no products does not confirm the formation of specific species.
- Conclusions drawn about undetected species are scientifically untenable.
Conclusions:
- The assertion of Fe3+ and HO• radical formation from the reaction of Fe(aq)2+ with H2O2(g) at the water-vapor interface, based on undetected species, is not supported.
- Further experimental evidence is required to validate proposed reaction mechanisms at the water-vapor interface.
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