Understanding the Surface Induced Phosphorylation of Prebiotic Molecules by Schreibersite

<p>The study of the surface of a meteoritic mineral, schreibersite (Fe,Ni)₃P, was investigated to provide insight into the role of the mineral’s surface in aqueous-phase phosphorylation reactions. The optimization of a custom-designed ultrahigh vacuum (UHV) apparatus and Fe₂NiP (schreibersite) surface was performed to permit surface science analysis. The bare surface was characterized by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), which showed some oxidation and segregation of phosphorous within the near-surface region. The interaction and/or reaction of water (H₂O), methanol (CH₃OH), formic acid (HCO₂H) and other molecules with the schreibersite surface at varying surface temperatures was probed by reflection absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD). At surface temperatures of approximately 130 K, H₂O interacts with Fe-P bridge sites while CH₃OH does not appear to interact with surficial phosphorus. The interaction between HCO₂H and surficial phosphorus is still under investigation. At 295 K, it is demonstrated that H₂O dissociatively chemisorbs as OH^-and lattice phosphorus undergoes oxidation. An increase in the surface temperature to about 500 K results in the recombinative desorption of OH^- as H₂O. Adsorption of other probe molecules such as H₂ and CO were not detected in the RAIRS experiments, and low dosages of pyridine (C₅H₅N) on the Fe₂NiP surface showed the presence of both Lewis and Brønsted acid sites.</p>

Name thesis:degree_name

Master of Science in Chemical Sciences (MSCB)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2016

Author dc:creator

• Qasim, Danna

Contributors dc:contributor

• Heather Abbott-Lyon
• Mark Mitchell
• Bharat Baruah

• RAIRS
• TPD
• Schreibersite
• Meteorite
• Prebiotic
• UHV
• Chemistry
• Geochemistry
• Physical Chemistry
• The Sun and the Solar System

Repository record dc:identifier

https://digitalcommons.kennesaw.edu/mscs_etd/8

OAI identifier oai:identifier

oai:digitalcommons.kennesaw.edu:mscs_etd-1007