AVS 61st International Symposium & Exhibition
    Atom Probe Tomography Focus Topic Thursday Sessions
       Session AP+AS+EN+NS+SS-ThA

Paper AP+AS+EN+NS+SS-ThA4
3D Nanoscale Chemical/Structure Analysis in Mineral Carbon Sequestration Study using Atom Probe Tomography

Thursday, November 13, 2014, 3:20 pm, Room 301

Session: APT and FIM Analysis of Catalysts and Nanomaterials
Presenter: Jia Liu, Pacific Northwest National Laboratory
Authors: J. Liu, Pacific Northwest National Laboratory
D.E. Perea, Pacific Northwest National Laboratory
R.J. Colby, Pacific Northwest National Laboratory
L. Kovarik, Pacific Northwest National Laboratory
B. Arey, Pacific Northwest National Laboratory
O. Qafoku, Pacific Northwest National Laboratory
A. Felmy, Pacific Northwest National Laboratory
Correspondent: Click to Email
Mineral carbon sequestration is one of the important means to store CO2 in order to mitigate the environmental concern regarding ever-growing anthropogenic CO2 emissions. Olivines, X2SiO4 where X = Mg and Fe, hold promise as potential media to sequester carbon due to its broad availability in basalt deposits and reactivity to form stable metal carbonates. Site-specific reactivity of olivine with supercritical CO2 is of great interest in understanding the fundamental elementary reaction mechanisms, where the presence of impurities within the bulk mineral may affect reaction kinetics. A combination of atom probe tomography (APT) and scanning transmission electron microscopy (STEM) is being used to map the complex composition and nanoscale structure across various site-specific regions. APT analysis of unreacted natural fayalite indicates the presence of 2-3-nm-thick hydrated iron oxide layers. In addition, Na impurities were found to concentrate within the hydrated layers while Mg and Mn were depleted from these regions. With the ability of APT to detect the chemical/structural heterogeneity at nanometer-scale, we find that APT will provide a means to correlate with ongoing experimental reaction studies and also provide guidance into models of the heterogeneous phase formation and reaction rates at precisely defined interfaces within minerals.