Mineralogy exerts control on organic molecules zonal structuring and reordering
EMSL Project ID
51672
Abstract
Organic C preservation in soil environments is predominantly driven by organic matter: soil mineral interactions. Yet, mechanistic uncertainties remain, namely how spatial variation in mineralogy controls environmental persistence of organic compounds. We propose to directly and in real-time probe at nanoscale the identity of organic compounds at the mineral-bound (contact) zone and at the organic-interaction (outer) zone. We will then assess how mineralogy influences the partitioning of organic molecules in each zone. Direct, in situ and thus in real-time experimental measurements of a conceptual organic-mineral association "zonal" model, proposed by Kleber et al., 2007, have not yet been performed. We will employ a recently developed EMSL approach to, for the first time with precision and high-resolution, probe reaction dynamics at organo: mineral interface (contact zone) and elucidate the structure of associations at the organic-interaction (outer) zone. We then will evaluate organo: mineral stability, using a ramp pyrolysis method under hypothesis that mineral-bound organic compounds represent a new chemical state that is energetically more stable compared to unbound organics. Molecular dynamic (MD) simulations will predict and guide our interpretation on modes of organo: mineral associations and validate this study experimental results. This research is aligned with EMSL roadmap for improving predictive models for environmental systems and will contribute to complexation models that lack this type of measurements
Project Details
Start Date
2020-11-25
End Date
2023-06-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members