Nanoscale Morphology and Mineral Phase Distribution During Hydroxylation and Carbonation Cycling of Magnesium Oxide

Anthropogenic carbon emissions are noticeably changing our environment and consequentially affecting us as a species. In combination with other approaches, mineral looping is a promising method for gigaton-scale carbon capture to diminish our impact on Earth as our energy-dependent technological advance continues. We have been analyzing the structural transformation of magnesium oxide at the nanometric and molecular level to determine the optimal conditions and characteristic properties of its reaction with water and CO₂ to perform atmospheric carbon capture. From previous experiments, we have found carbonation process only lasts as long as the samples stays humidified. Besides, we also discovered that the reactions can occur multiple times even when changing from water to carbon dioxide flow and vice versa, maximizing the absorption of carbon with each cycle but at a diminishing rate. Continuing with our earlier findings, we trigger the reaction in an enclosed sample of MgO powder by flowing a controlled input of water and carbon dioxide and use in situ and batch mode x-ray scattering experiments to determine the concentration and the rate of change of the material for multiple iterations of this process.