Title
Geoelectrochemistry-driven alteration of amino acids to derivative organics in carbonaceous chondrite parent bodies
Author
Yamei Li, Norio Kitadai, Yasuhito Sekine, Hiroyuki Kurokawa, Yuko Nakano & Kristin Johnson-Finn
Year
2022
Journal
Nature Communications
Abstract
A long-standing question regarding carbonaceous chondrites (CCs) is how the CCs’ organics were sourced and converted before and after the accretion of their parent bodies. Growing evidence shows that amino acid abundances in CCs decrease with an elongated aqueous alteration. However, the underlying chemical processes are unclear. If CCs’ parent bodies were water-rock differentiated, pH and redox gradients can drive electrochemical reactions by using H2 as an electron source. Here, we simulate such redox conditions and demonstrate that α-amino acids are electrochemically altered to monoamines and α-hydroxy acids on FeS and NiS catalysts at 25 °C. This conversion is consistent with their enrichment compared to amino acid analogs in heavily altered CCs. Our results thus suggest that H2 can be an important driver for organic evolution in water-rock differentiated CC parent bodies as well as the Solar System icy bodies that might possess similar pH and redox gradients.
Full Article
Instrument
LC-2000
Keywords
amino acids, CCs, Carbonaceous chondrites,