Abstract
Olivine (magnesium iron silicate) is a prime contender for CO2 mineralization in aqueous environments via natural weathering or industrial processes. However, upon its dissolution a silica-rich alteration layer (SAL) gets formed, which can drastically slow down the chemical reactions at the mineral-electrolyte interface. Despite extensive research, the SAL’s nature and variability remain to be clarified. SAL porosity, thickness and chemical composition all play a role and can evolve. Sulfuric acid is known to expedite olivine dissolution. However, there is conflicting evidence regarding the role of iron oxidation in the passivation of SALs.
To get more insight into Olivine SALs, we used Confocal Raman, Scanning Electron, and Fluorescence Liftetime Imaging Microscopies. We monitored the dissolution kinetics and interfacial layer formation in sulfuric, hydrochloric, and nitric acid at varying pH levels. Our findings underscore the significant influence of electrolyte chemistry on the interfacial layer's formation, composition and growth.
A comprehensive understanding of the layer formation holds the potential to yield invaluable insights into olivine weathering kinetics, thereby paving the way for enhanced olivine-based CCS strategies.
To get more insight into Olivine SALs, we used Confocal Raman, Scanning Electron, and Fluorescence Liftetime Imaging Microscopies. We monitored the dissolution kinetics and interfacial layer formation in sulfuric, hydrochloric, and nitric acid at varying pH levels. Our findings underscore the significant influence of electrolyte chemistry on the interfacial layer's formation, composition and growth.
A comprehensive understanding of the layer formation holds the potential to yield invaluable insights into olivine weathering kinetics, thereby paving the way for enhanced olivine-based CCS strategies.
| Original language | English |
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| Publication status | Published - 25 Feb 2024 |
| Event | WE Heraeus Seminar on Solid-Water-Interfaces at the Molecular Level 2024 - Physikzentrum, Bad Honnef, Germany Duration: 25 Feb 2024 → 1 Mar 2024 |
Conference
| Conference | WE Heraeus Seminar on Solid-Water-Interfaces at the Molecular Level 2024 |
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| Country/Territory | Germany |
| City | Bad Honnef |
| Period | 25/02/24 → 1/03/24 |
| Other | Solid-water interfaces are ubiquitous both in nature and technology. For example, mineral-water interfaces are at the heart of fundamental processes taking place in nature, including weathering, dissolution and growth of rocks, biomineralization as well as buffering of the seawater pH value. Likewise, numerous industrial and everyday life processes involve solid-water interfaces, in fields ranging from seawater desalination and incrustation inhibition to electrochemistry and catalysis. A comprehensive understanding of these processes requires elucidating the interfacial structure, chemical composition and charge distribution at the molecular scale. So far, however, many fundamental details of the interface remain unknown. Moreover, solid-water interfaces are often modelled using continuum theories, which will break down at the interface. Very recent advances in experiment and theory now enable to gain unprecedented insights into solid-water interfaces and elucidate molecular-level mechanisms at play. In this seminar, we will bring together renowned experts and young investigators in an open and an inspiring atmosphere to foster in-depth discussions. Recent advances in experimental and theoretical approaches for studying solid-water interfaces will be presented. We will discuss implications for understanding molecular-level mechanisms in fields such as biomineralization, ice nucleation as well as electrochemical applications. |