γ-Ray Driven Aqueous-Phase Methane Conversions into Complex Molecules up to Glycine.

Area of Science:

• Astrochemistry and Astrobiology
• Radiochemistry
• Catalysis

Background:

• Understanding the origin of organic molecules in the universe is crucial.
• Methane (CH4) is an abundant simple molecule present in cosmic environments.
• Efficient conversion of methane into valuable products under mild conditions remains a challenge.

Purpose of the Study:

• To investigate gamma-ray driven aqueous-phase conversion of methane.
• To explore the formation of organic compounds, including glycine, from methane.
• To evaluate the effect of solid catalysts on methane conversion efficiency and product selectivity.

Main Methods:

• Utilized gamma rays as an external energy source for aqueous methane conversion.
• Introduced oxygen and ammonia to facilitate product formation.
• Tested various solid granules, including silicon dioxide (SiO2), as catalysts.

Main Results:

• Gamma rays efficiently drove methane conversion in aqueous phase at room temperature.
• Formation of glycine was observed with the addition of ammonia.
• Silicon dioxide (SiO2) significantly modified product distribution, achieving up to 82% selectivity for acetic acid (CH3COOH).

Conclusions:

• Gamma-ray driven aqueous methane conversion is a plausible mechanism for the formation of early complex organic compounds in the universe.
• This method offers an alternative strategy for the efficient utilization of methane as a carbon source.
• Mild reaction conditions and high selectivity achieved with SiO2 highlight potential for industrial applications in heterogeneous catalysis.