Platinum Carbonates in Aqueous Fluids under Extreme Conditions

Area of Science:

• Geochemistry
• Mineralogy
• Computational Chemistry

Background:

• Platinum is a rare element crucial for understanding Earth's deep processes.
• Platinum transport in geological fluids is key to identifying new deposits.
• The role of carbonates in platinum speciation under pressure is poorly understood.

Purpose of the Study:

• To investigate platinum-carbonate complexation in aqueous fluids at high pressure and temperature.
• To predict platinum speciation changes with pressure and oxidation state.
• To identify spectroscopic signatures for characterizing platinum species.

Main Methods:

• Extensive first-principles molecular simulations.
• Modeling at 1 GPa and 11 GPa, 1000 K.
• Computation of Raman spectra for vibrational signature identification.

Main Results:

• Detailed speciation of platinum (bi)carbonates predicted under relevant Earth conditions.
• Pressure and oxidation state effects on platinum speciation elucidated.
• Distinct vibrational signatures for various platinum species identified.

Conclusions:

• This research fills a critical knowledge gap in platinum geochemistry.
• The findings offer new insights into platinum transport mechanisms in the deep Earth.
• Computed spectra provide a tool for analyzing natural samples and refining geochemical models.