solid state theory walter a harrison pdf

In fact, aqueous solutions in deep Earth are often confined to the nanoscale in pores, grain boundaries, and fractures of Earth’s materials 12, 13, 14, where the physical and chemical properties of solutions may be dramatically different from those of bulk solutions. Most of the previous studies focus on the properties of aqueous carbon solutions in the bulk phase. It has long been assumed that aqueous carbon solutions under extreme pressure (P) and temperature (T) conditions are made by mixtures of neutral gas molecules 4, e.g., H 2O, CO 2, CH 4 however, recent studies showed that important chemical reactions occur between water and carbon species, resulting in significant amounts of ionic products, which may further participate in water-rock interactions and the formation of diamonds in Earth’s interior 5, 6, 7, 8, 9, 10, 11. Our findings suggest that CO 2(aq) in deep Earth is more active than previously thought, and confining CO 2 and water in nanopores may enhance the efficiency of mineral carbonation.Īqueous fluids play a critical role in transporting carbon between Earth’s surface and interior 1, 2, 3, which is a substantial part of Earth’s carbon cycle, with great implications for global climate and human energy consumption. The stishovite-water interface makes the solutions more acidic, which shifts the chemical equilibria, and the interface chemistry also significantly affects the reaction mechanisms. We find that CO 2(aq) reacts more in nanoconfinement than in bulk. Here, we apply extensive ab initio molecular dynamics simulations to study aqueous carbon solutions nanoconfined by graphene and stishovite (SiO 2) at 10 GPa and 1000 ~ 1400 K.

Previous studies focus on the CO 2(aq) solutions in the bulk phase, but underground aqueous solutions are often confined to the nanoscale, and nanoconfinement and solid-liquid interfaces may substantially affect chemical speciation and reaction mechanisms, which are poorly known on the molecular scale. The reactions of CO 2 in water under extreme pressure-temperature conditions are of great importance to the carbon storage and transport below Earth’s surface, which substantially affect the carbon budget in the atmosphere.

Solid state theory walter a harrison pdf