Oxidation States of Iron in Schreibersite Analog Reactions
Advisor(s)
Dr. Christopher Spiese
Confirmation
1
Document Type
Poster
Location
ONU McIntosh Center; Activities Room
Start Date
24-4-2026 12:00 PM
End Date
24-4-2026 12:50 PM
Abstract
The oxidation state of metals in solution after a reaction can give some indication of the mechanism of the reaction. Residual metals can be analyzed to study this effect. Iron, which appears in primarily ferric (3+) and ferrous (2+) states, has been found in unusual oxidation patterns in the Jezero Crater on Mars. A suspected cause of these patterns is the meteoric compound schreibersite ((Fe,Ni)3P). To test this theory, iron phosphide (Fe3P) is used as an analogous compound under oxygen-free atmospheres to determine what oxidation states of iron are left after schreibersite reacts in solution. The experiment was run in five different solutions containing sulfate, metallic salts, and/or organic solvents and under two atmospheric conditions (nitrogen or carbon dioxide). To determine oxidation states, a standard colorimetric method was run alongside atomic emission spectroscopy. These methods allow for the calculation of ferrous, ferric, and total soluble iron. Over the course of the year, sample preparation and characterization have been improved to minimize oxygen interference and get consistent data. In all solutions, iron appeared in high concentration, though the solution containing sulfate, metallic salts, and organic solvents showed the greatest concentration of total iron. Ferrous iron was the dominant species in all solutions.
Recommended Citation
Pacek, Emily Joy and Spiese, Christopher, "Oxidation States of Iron in Schreibersite Analog Reactions" (2026). ONU Student Research Colloquium. 64.
https://digitalcommons.onu.edu/student_research_colloquium/2026/Posters/64
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Oxidation States of Iron in Schreibersite Analog Reactions
ONU McIntosh Center; Activities Room
The oxidation state of metals in solution after a reaction can give some indication of the mechanism of the reaction. Residual metals can be analyzed to study this effect. Iron, which appears in primarily ferric (3+) and ferrous (2+) states, has been found in unusual oxidation patterns in the Jezero Crater on Mars. A suspected cause of these patterns is the meteoric compound schreibersite ((Fe,Ni)3P). To test this theory, iron phosphide (Fe3P) is used as an analogous compound under oxygen-free atmospheres to determine what oxidation states of iron are left after schreibersite reacts in solution. The experiment was run in five different solutions containing sulfate, metallic salts, and/or organic solvents and under two atmospheric conditions (nitrogen or carbon dioxide). To determine oxidation states, a standard colorimetric method was run alongside atomic emission spectroscopy. These methods allow for the calculation of ferrous, ferric, and total soluble iron. Over the course of the year, sample preparation and characterization have been improved to minimize oxygen interference and get consistent data. In all solutions, iron appeared in high concentration, though the solution containing sulfate, metallic salts, and organic solvents showed the greatest concentration of total iron. Ferrous iron was the dominant species in all solutions.