Abstract

In recent times, the rising amount of carbon dioxide (CO2) in the atmosphere have caused a concerning increase in global warming. To combat global warming, several negative emissions technologies have been employed. One such technology is Enhanced Rock Weathering (ERW), wherein CO2 is trapped as thermodynamically stable carbonates in silicate minerals that are exposed to the atmosphere. This process happens via mineral carbonation. Wollastonite (CaSiO3) is one such silicate that has applications in ERW. Our study is focused on utilizing density functional theory-based calculations to investigate the thermodynamic stability of oxygen vacancies on the surfaces of wollastonite mineral. Formation of oxygen vacancy naturally requires large amounts of energy. Oxygen vacancy formation is more favorable on the surface rather than in the bulk of the wollastonite mineral. We further studied if adding dopants (aluminum dopants) on the surface of the mineral is thermodynamically favorable and evaluated their overall impact on oxygen vacancy formation. Formation of oxygen vacancies on the wollastonite surfaces is found to be an endothermic process, whereas addition of aluminum dopants makes it an exothermic process. This fundamental knowledge will be instrumental in enhancing the reactivity of wollastonite minerals for effective sequestration of carbon dioxide using ERW.

Publication Date

8-8-2022

Document Type

Thesis

Student Type

Graduate

Degree Name

Materials Science and Engineering (MS)

Department, Program, or Center

School of Chemistry and Materials Science (COS)

Advisor

Pratik Dholabhai

Advisor/Committee Member

Bruce E. Kahn

Campus

RIT – Main Campus

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